Hectic fever is typical for. Fever: basic information

Characterized by a temporary increase in body temperature due to the dynamic restructuring of the thermoregulation system under the influence of pyrogens (substances that cause an increase in temperature).

In evolution, fever arose as a protective and adaptive reaction to infection in the organism of higher animals and humans, therefore, in addition to an increase in body temperature, other phenomena characteristic of infectious pathology are also observed during this process. Fever is usually accompanied by hot flashes.

In the past, all diseases accompanied by a rise in body temperature were called "fever", but in the modern scientific understanding, fever is not a disease. However, in modern titles a number of nosological units term fever present, for example, spotted fever, Rocky Mountain fever, pappatachi fever, hemorrhagic fever, Ebola, etc.

The essence of fever lies in such a response of the thermoregulatory apparatus of higher homoiothermal animals and humans to specific substances (pyrogens), which is characterized by a temporary shift of the set point of temperature homeostasis to a higher level, with mandatory preservation of the mechanisms of thermoregulation themselves, which is the fundamental difference between fever and hyperthermia.

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pyrogens

pyrogens- These are substances that, getting into the body from the outside or being formed inside it, cause fever. Exogenous pyrogens are most often components of infectious pathogens. The strongest of them are capsular thermostable lipopolysaccharides of Gram-negative bacteria. Exogenous pyrogens act indirectly, through endogenous pyrogens, which provide a shift in the set point in the hypothalamic thermoregulation center. Most endogenous pyrogens are of leukocyte origin, for example, interleukins 1 and 6, tumor necrosis factor, interferons, macrophage inflammatory protein-1α, many of which, in addition to pyrogenic (due to their ability to induce prostaglandin synthesis), also have a number of other important effects. Cells are the main source of endogenous pyrogens. immune system(monocytes, macrophages, T- and B-lymphocytes), as well as granulocytes. The formation and release of pyrogens by these cells occurs under the action of the following factors: endogenous pyrogens, inflammation of any etiology, "pyrogenic" steroids, etc.

Development mechanism

Stages of fever

In its development, fever always goes through 3 stages. In the first stage, the temperature rises stadia incrementi), on the second - it is kept for some time at an elevated level ( stadia fastigi or acme), and on the third - decreases to the original ( stadia decrementi).

Rise in temperature associated with the restructuring of thermoregulation in such a way that heat production begins to exceed heat transfer. Moreover, in adults, it is precisely the restriction of heat transfer that is most important, and not an increase in heat production. This is much more economical for the body, since it does not require an increase in energy consumption. In addition, this mechanism provides a high rate of heating of the body. In newborn children, on the contrary, an increase in heat production comes to the fore.

The restriction of heat transfer occurs due to the narrowing of peripheral vessels and a decrease in the influx of warm blood into the tissues. The most important is the spasm of the skin vessels and the cessation of sweating under the influence of the sympathetic nervous system. The skin turns pale, and its temperature drops, limiting heat transfer due to radiation. Reducing sweat formation limits heat loss through evaporation. Muscle contraction hair follicles leads to ruffled wool in animals, creating an additional heat-insulating air layer, and in humans it manifests itself as the phenomenon of "goosebumps".

The emergence of subjective feeling chills is directly related to a decrease in skin temperature and irritation of skin cold thermoreceptors, the signal from which goes to the hypothalamus, which is an integrative center of thermoregulation. Further, the hypothalamus signals the situation to the cortex, where the appropriate behavior is formed: taking the appropriate posture, wrapping up. The decrease in skin temperature explains the muscle trembling, which is caused by the activation of the trembling center, localized in the midbrain and medulla oblongata.

Due to the activation of metabolism in the muscles, heat production increases (contractile thermogenesis). At the same time, non-shivering thermogenesis intensifies in such internal organs as the brain, liver, and lungs.

temperature hold starts when the setpoint is reached and can be short (hours, days) or long (weeks). At the same time, heat production and heat transfer balance each other, and a further increase in temperature does not occur, thermoregulation occurs according to mechanisms similar to the norm. At the same time, the skin vessels expand, pallor disappears, and the skin becomes hot to the touch, and trembling and chills disappear. At the same time, the person experiences a feeling of heat. At the same time, diurnal temperature fluctuations persist, but their amplitude sharply exceeds the normal one.

Depending on the severity of the rise in temperature in the second stage, fever is divided into subfebrile(up to 38 °C), weak(up to 38.5 °C), moderate (febrile)(up to 39 °C), high (pyretic)(up to 41 °C) and excessive (hyperpyretic)(over 41 °C). Hyperpyretic fever is life-threatening, especially in children.

temperature drop may be gradual or abrupt. The stage of temperature reduction begins after the exhaustion of the supply of exogenous pyrogens or the cessation of the formation of endogenous pyrogens under the influence of internal (natural) or exogenous (drug) antipyretic factors. After the termination of the effect of pyrogens on the thermoregulatory center, the set point drops to a normal level, and the temperature begins to be perceived by the hypothalamus as elevated. This leads to the expansion of skin vessels and the excess heat for the body is now removed. There is profuse sweating, increased diuresis and perspiration. Heat transfer at this stage sharply exceeds heat production.

Types of fevers according to the nature of daily temperature fluctuations:

1. Persistent fever (febris continua)- prolonged steady increase in body temperature, daily fluctuations do not exceed 1 ° C.
2. relapsing fever (febris remittens)- significant daily fluctuations in body temperature within 1.5-2°C. But at the same time, the temperature does not drop to normal numbers.
3. intermittent fever (febris intermittis)- characterized by a rapid, significant increase in temperature, which lasts for several hours, and then is replaced by a rapid drop to normal values.
4. Hectic or wasting fever (febris hectica)- diurnal fluctuations reach 3-5°C, while temperature rises with a rapid decline can be repeated several times during the day.
5. perverted fever (febris inversa)- it is characterized by a change in the daily rhythm with higher temperature rises in the morning.
6. wrong fever (febris athypica)- which is characterized by temperature fluctuations during the day without a definite pattern.
7. relapsing fever (febris recurrences)- characterized by alternating periods of temperature increase with periods of normal temperature, which last for several days.

Etiology

The fever is constant symptom almost all acute infectious diseases and some chronic ones during an exacerbation, and in these cases the pathogen is often present in the blood (bacteremia) or even multiplies in it (sepsis, septicopyemia). Therefore, etiologically, fever can be established by isolating the pathogen from the blood (hemoculture) in the same way as from the primary focus of localization. It is more difficult to determine the etiology of fever in diseases caused by opportunistic microbes, especially when the primary focus of the pathogen is “masked”. In these cases, along with a blood test for a wide range of pathogens, urine, bile, sputum and bronchial washings, mucus from the nose, pharynx, sinuses, cervical contents, etc. are also examined. anemia...)

Pediatrics

Vital signs against the background of temperature readings provide important diagnostic information. Tachycardia disproportionate to fever, possibly due to hypohedria or

What are the main mechanisms for the development of fever?

Fever is an increase in body temperature due to a violation and restructuring of thermoregulation processes. The appearance of fever is associated with the formation in the patient's body of specific substances (pyrogens) that change the functional activity of thermoregulation centers. Most often, various pathogenic bacteria and viruses, as well as their decay products, act as pyrogens. Therefore, fever is the leading symptom of many infectious diseases.

In what cases can a patient have a fever?

Feverish reactions can also be observed in inflammations of a non-infectious nature (aseptic), which are caused by mechanical, chemical and physical damage. Fever is also accompanied by tissue necrosis, which develops as a result of circulatory disorders, for example, with myocardial infarction. Feverish conditions are observed in malignant tumors, some endocrine diseases that occur with an increase in metabolism (thyrotoxicosis), allergic reactions, violation of the functions of the central nervous system (thermoneuroses) "etc.

In many cases (taking into account the nature of fever, the age of patients, concomitant diseases), fever can play an extremely unfavorable role in the course of diseases and their outcome. Therefore, the treatment of fever in each specific situation requires an individual and differentiated approach.

What factors determine the severity of the febrile reaction?

The severity of the febrile reaction depends not only on the disease that caused it, but also to a large extent on the reactivity of the organism. So, in elderly people, debilitated patients, some inflammatory diseases, such as acute pneumonia, can occur without severe fever. In addition, patients subjectively tolerate a rise in temperature in different ways.

What is pyrotherapy?

An artificially induced increase in body temperature (pyrotherapy) is sometimes used for medicinal purposes, in particular, for a number of sluggish infections.

How is fever divided according to the degree of temperature increase?

According to the degree of increase in body temperature, subfebrile (not higher than 38 ° C), moderate (38-39 ° C), high (39-41 ° C) and excessive, or hyperpyretic (over 41 ° C), fever are distinguished. Fever often follows a diurnal rhythm of fluctuations when more heat observed in the evening, and a lower one - in the morning.

How is fever divided according to the duration of the course?

According to the duration of the course, a fleeting (lasting several hours), acute (up to 15 days), subacute (15-45 days) and chronic (over 45 days) fever are distinguished.

What types of temperature curves are distinguished in clinical practice?

With a long course of febrile illness, various types of fever, or types of temperature curves, can be observed. It is a constant, relapsing, hectic, perverted and irregular fever.

Depending on the forms of temperature curves, there are recurrent fever with a clear alternation of febrile and fever-free periods and undulating fever, which is characterized by a gradual increase, and then the same smooth decrease in body temperature.

According to the rate of temperature decrease, critical and lytic temperature drops are distinguished.

What is persistent fever?

Constant fever, which occurs, for example, with croupous pneumonia, is distinguished by the fact that daily temperature fluctuations in it do not exceed 1 ° C.

What is relapsing and intermittent fever?

With relapsing, or laxative, fever, daily temperature fluctuations exceed 1 ° C, and there are no periods of normal temperature, for example, in the morning.

Intermittent fever is also characterized by daily fluctuations in temperature above 1 ° C, however, in the morning, it decreases to a normal level.

What is characteristic of hectic fever?

Hectic, or exhausting, fever, observed, for example, in sepsis, is characterized by a sharp rise and a rapid drop in temperature to normal values, so that daily temperature fluctuations reach 4-5 ° C. In some patients, such temperature jumps (“candles”) occur several times during the day, significantly worsening the condition of patients.

What is perverted and wrong fever?

Perverted fever is manifested by a change in the usual daily rhythm of temperature, so that a higher temperature is recorded in the morning, and a lower one in the evening.

Irregular fever is characterized by the absence of patterns of fluctuations during the day.

What kind of care does the patient need during the period of fever?

In the first stage of fever, when there is an increase in temperature, the patient has muscle tremors, headache, and malaise. During this period, the patient must be warmed, put to bed and carefully monitor the state of various organs and body systems.

What care is needed for a patient during a period of constantly elevated temperature?

In the second stage of fever, the temperature is constantly elevated, which is characterized by a relative balance in the processes of heat production and heat transfer. During this period, chills and muscle tremors subside, but general weakness, headache, and dry mouth are observed. In the second stage, pronounced changes in the central nervous system, as well as the cardiovascular system, can be observed. At the height of fever, delusions and hallucinations are possible, and in young children, convulsions. It is necessary at this time to carefully care for the oral cavity of patients, lubricate the cracks in the mouth, etc., food is prescribed fractional, and drinking is plentiful. With a long stay of patients in bed, they carry out mandatory prevention of bedsores.

What are the features of patient care in the stage of lowering the temperature?

The third stage of fever - the stage of temperature decrease or decrease is characterized by a significant predominance of heat transfer over heat production due to the expansion of peripheral blood vessels, a significant increase in sweating.

What is the lysis and crisis of a temperature patient?

The slow drop in temperature that occurs over several days is called lysis. A rapid, often within 5-8 hours, drop in temperature from high values ​​​​(39-40 ° C) to normal and even subnormal values ​​\u200b\u200bis called a crisis.

What is the danger of a crisis for the patient?

As a result of a sharp restructuring of the mechanisms of regulation of the cardiovascular system, a crisis can carry with it the danger of developing a collaptoid state - acute vascular insufficiency, which is manifested by severe weakness, profuse sweating, pallor and cyanosis of the skin, a drop in blood pressure, increased heart rate and a decrease in its filling up to before the appearance of a thread.

How is patient care provided during a crisis?

A critical drop in body temperature requires medical workers to take appropriate measures: the introduction of drugs that stimulate the respiratory and vasomotor center (cordiamin, caffeine, camphor), which increase heart rate and increase blood pressure (adrenaline, norepinephrine, mezaton, cardiac glycosides, corticosteroid hormones and etc.).

The patient is covered with heating pads, warm, give him strong hot tea or coffee, change his underwear in a timely manner. to linens.

Compliance with all requirements for the care of febrile patients, constant monitoring of their condition, primarily the functions of the respiratory and circulatory organs, can prevent the development of serious complications in time and contribute to the speedy recovery of patients.

An analysis of the temperature response makes it possible to assess the height, duration and types of temperature fluctuations, as well as the nature of the accompanying temperature fluctuations. clinical manifestations illness.

Types of fevers

There are the following types of fevers in children:

short-term fever (up to 5-7 days) with suspected localization, in which the diagnosis can be made on the basis of clinical history and physical findings, with or without laboratory tests;

fever without a focus, for which the history and physical examination do not suggest a diagnosis, but laboratory tests may reveal an etiology;

Fever of unknown origin (FUO);

subfebrile conditions

Feverish reactions are evaluated depending on the level of temperature rise, the duration of the febrile period and the nature of the temperature curve.

Types of febrile reactions depending on the degree of increase in body temperature

Only some diseases are manifested by characteristic, pronounced temperature curves; however, it is important to know their types in order to conduct differential diagnosis. It is not always possible to accurately compare typical changes with the onset of the disease, especially with early antibiotic therapy. However, in some cases, the nature of the onset of fever may suggest a diagnosis. So, a sudden onset is typical for influenza, meningitis, malaria, subacute (2-3 days) - for typhus, ornithosis, Q fever, gradual - typhoid fever, brucellosis.

According to the nature of the temperature curve, several types of fevers are distinguished.

Persistent fever(febris continua) - the temperature exceeds 390C, the differences between morning and evening body temperature are insignificant (maximum 10C). Body temperature remains evenly high throughout the day. This type of fever occurs in untreated pneumococcal pneumonia, typhoid fever, paratyphoid fever, and erysipelas.

laxative(remitting) fever(febris remittens) - daily temperature fluctuations exceed 10C, and it can drop below 380C, but does not reach normal numbers; observed in pneumonia, viral diseases, acute rheumatic fever, juvenile rheumatoid arthritis, endocarditis, tuberculosis, abscesses.

intermittent(intermittent) fever(febris intermittens) - daily fluctuations in the maximum and minimum temperatures of at least 10C, periods of normal and elevated temperatures often alternate; a similar type of fever is inherent in malaria, pyelonephritis, pleurisy, sepsis.

debilitating, or hectic, fever(febris hectica) - the temperature curve resembles that of laxative fever, but its daily fluctuations are more than 2-30C; a similar type of fever may occur in tuberculosis and sepsis.

relapsing fever(febris recurrens) - high fever for 2-7 days, alternating with periods of normal temperature, lasting several days. The feverish period begins suddenly and also ends abruptly. A similar type of febrile reaction is observed with relapsing fever, malaria.

undulating fever(febris undulans) - is manifested by a gradual increase in temperature from day to day to high numbers, followed by a decrease in it and the re-formation of individual waves; a similar type of fever occurs with lymphogranulomatosis and brucellosis.

perverted(inverse) fever(febris inverse) - there is a perversion of the daily temperature rhythm with higher temperature rises in the morning hours; a similar type of fever occurs in patients with tuberculosis, sepsis, tumors, and is characteristic of some rheumatic diseases.

Wrong or atypical fever(irregularis or febris atypical) - a fever in which there are no patterns of rise and fall in temperature.

Monotonous type of fever - with a small range of fluctuations between morning and evening body temperature;

It should be noted that at present, typical temperature curves are rare, which is associated with the use of etiotropic and antipyretic drugs. medicines.

According to the nature of fluctuations in body temperature during the day (sometimes for a longer period), the following types of fevers (types of temperature curves) are distinguished.

1. Persistent fever (febris continua). Fluctuations in body temperature during the day do not exceed 1°C, usually within 38-39°C. Such a fever is characteristic of acute infectious diseases (Figure 6).

2. Relapsing or laxative fever (febris remittens): prolonged fever with daily fluctuations in body temperature exceeding 1 ° C (up to 2 ° C), without decreasing to a normal level. It is characteristic of many infections, focal pneumonia, pleurisy, purulent diseases (Figure 7).

3. Hectic or wasting fever (febris hectica): daily fluctuations in body temperature are very pronounced (3-5 ° C) with a fall to normal or subnormal values. Such fluctuations in body temperature can occur several times a day. Hectic fever is characteristic of sepsis, abscesses - abscesses (for example, of the lungs and other organs), miliary tuberculosis (Figure 8).

4. Intermittent or intermittent fever (febris intermittens). Body temperature quickly rises to 39-40°C and within a few hours (i.e. quickly) drops to normal. After 1 or 3 days, the rise in body temperature is repeated. Thus, there is a more or less correct change of high and normal body temperature within a few days. This type of temperature curve is characteristic of malaria (Figure 9).

5. Relapsing fever (febris recurrences): unlike intermittent fever, a rapidly rising body temperature remains at an elevated level for several days, then temporarily decreases to normal, followed by a new increase, and so on repeatedly. Such a fever is characteristic of relapsing fever (Figure 10).

6 Perverse Fever (febris inversa) or reverse type fever: with such a fever, the morning body temperature is higher than the evening. This type of temperature curve is characteristic of tuberculosis (Figure 11).

7. Wrong fever (febris irregularis, febris atypica): fever of indeterminate duration, with irregular and varied diurnal fluctuations. It is typical for influenza, rheumatism (Figure 12).

Rice. 8. Exhausting fever. 9. Intermittent fever

Rice. 11. Perverted fever. 12. Wrong fever

Rice. 13. Wave-like fever

Concept definition

Fever is an increase in body temperature as a result of changes in the thermoregulatory center of the hypothalamus. It is a protective and adaptive reaction of the body that occurs in response to the action of pathogenic stimuli.

Hyperthermia should be distinguished from fever - an increase in temperature, when the process of thermoregulation of the body is not disturbed, and an elevated body temperature is due to changes in external conditions, for example, overheating of the body. Body temperature during infectious fever usually does not exceed 41 0 C, in contrast to hyperthermia, in which it is above 41 0 C.

Temperatures up to 37 °C are considered normal. Body temperature is not a constant value. The temperature value depends on: time of day(the maximum daily fluctuations are from 37.2 °С at 6 am to 37.7 °С at 4 pm). Night workers may have the opposite relationship. The difference between morning and evening temperature in healthy people does not exceed 1 0 C); motor activity(Rest and sleep help to lower the temperature. Immediately after eating, there is also a slight increase in body temperature. Significant physical exertion can cause a temperature increase of 1 degree); phases of the menstrual cycleamong women with a normal temperature cycle, the morning vaginal temperature curve has a characteristic biphasic shape. The first phase (follicular) is characterized by a low temperature (up to 36.7 degrees), lasts about 14 days and is associated with the action of estrogens. The second phase (ovulation) is manifested by a higher temperature (up to 37.5 degrees), lasts about 12-14 days and is due to the action of progesterone. Then, before menstruation, the temperature drops and the next follicular phase begins. The absence of a decrease in temperature may indicate fertilization. Characteristically, the morning temperature, measured in the axilla, in the oral cavity, or in the rectum, gives similar curves.

Normal body temperature in the armpit:36.3-36.9 0 C, in the oral cavity:36.8-37.3 0 , in the rectum:37.3-37.7 0 C.

Causes

The causes of fever are many and varied:

1. Diseases that directly damage the centers of thermoregulation of the brain (tumors, intracerebral hemorrhages or thromboses, heat stroke).

3. Mechanical injury (disintegration).

4. Neoplasms (Hodgkin's disease, lymphomas, leukemia, kidney carcinomas, hepatomas).

5. Acute metabolic disorders (thyroid crisis, adrenal crisis).

6. Granulomatous diseases (sarcoidosis, Crohn's disease).

7. Immune disorders (diseases connective tissue, drug allergy, serum sickness).

8. Acute vascular disorders (thrombosis, heart attacks of the lung, myocardium, brain).

9. Violation of hematopoiesis (acute hemolysis).

10. Under the influence of medications (malignant neuroleptic syndrome).

Mechanisms of emergence and development (pathogenesis)

The human body temperature is a balance between the formation of heat in the body (as a product of all metabolic processes in the body) and the release of heat through the surface of the body, especially the skin (up to 90-95%), as well as through the lungs, feces and urine. These processors are regulated by the hypothalamus, which acts like a thermostat. In conditions that cause an increase in temperature, the hypothalamus instructs the sympathetic nervous system to vasodilate the blood vessels of the skin, increased sweating which increases heat transfer. When the temperature drops, the hypothalamus gives the command to retain heat by constricting the blood vessels of the skin, muscle tremors.

endogenous pyrogen - a low molecular weight protein produced by blood monocytes and macrophages in the tissues of the liver, spleen, lungs, and peritoneum. In some tumor diseases - lymphoma, monocytic leukemia, kidney cancer (hypernephroma) - there is an autonomous production of endogenous pyrogen and, therefore, fever is present in the clinical picture. Endogenous pyrogen, after being released from cells, acts on thermosensitive neurons in the preoptic region of the hypothalamus, where, with the participation of serotonin, the synthesis of prostaglandin E1, E2 and cAMP is induced. These biologically active compounds, on the one hand, cause an intensification of heat production by restructuring the hypothalamus to maintain the body temperature at a higher level, and on the other hand, they affect the vasomotor center, causing constriction of peripheral vessels and a decrease in heat transfer, which generally leads to fever. The increase in heat production occurs due to an increase in the intensity of metabolism, mainly in muscle tissue.

In some cases, stimulation of the hypothalamus may not be caused by pyrogens, but by dysfunctions of the endocrine system (thyrotoxicosis, pheochromocytoma) or the autonomic nervous system (neurocirculatory dystonia, neuroses), the influence of certain medications (drug fever).

The most common causes of drug fever are penicillins and cephalosporins, sulfonamides, nitrofurans, isoniazid, salicylates, methyluracil, novocainamide, antihistamines, allopurinol, barbiturates, intravenous infusions of calcium chloride or glucose, etc.

Fever of central origin is caused by direct irritation of the thermal center of the hypothalamus as a result of an acute violation cerebral circulation, tumors, traumatic brain injury.

Thus, an increase in body temperature may be due to the activation of the system of exopyrogens and endopyrogens (infections, inflammation, pyrogenic substances of tumors) or other reasons without the participation of pyrogens at all.

Since the degree of increase in body temperature is controlled by the "hypothalamic thermostat", even in children (with their immature nervous system) fever rarely exceeds 41 0 C. In addition, the degree of temperature rise largely depends on the state of the patient's body: with the same disease, it can be different for different people. For example, with pneumonia in young people, the temperature reaches 40 0 ​​C and above, and in old age and in malnourished persons, such a significant rise in temperature does not occur; sometimes it does not even exceed the norm.

Clinical picture (symptoms and syndromes)

The fever is considered acute", if it lasts no more than 2 weeks, the fever is called" chronic» with a duration of more than 2 weeks.

In addition, during a fever, a period of temperature increase, a period of fever peak and a period of temperature decrease are distinguished. The decrease in temperature occurs in different ways. A gradual, step-like decrease in temperature over 2-4 days with slight evening rises is called lysis. The sudden, rapid end of a fever with a drop in temperature to normal within a day is called crisis. As a rule, a rapid drop in temperature is accompanied by profuse sweating. This phenomenon was given special importance before the beginning of the era of antibiotics, since it symbolized the beginning of a period of recovery.

Elevated body temperature from 37 to 38 0 C is called subfebrile fever. Moderately elevated body temperature from 38 to 39 0 C is called febrile fever. High body temperature from 39 to 41 0 C is called pyretic fever. Excessively high body temperature (over 41 0 C) is a hyperpyretic fever. This temperature in itself can be life-threatening.

There are 6 main types of fever and 2 forms of fever.

It should be noted that our predecessors attached great importance to temperature curves in the diagnosis of diseases, but in our time all these classical types of fever are of little help in work, since antibiotics, antipyretics and steroid drugs change not only the nature of the temperature curve, but the whole clinical picture diseases.

Type of fever

1. Persistent or persistent fever. Constantly elevated body temperature is observed and during the day the difference between morning and evening temperature does not exceed 1 0 C. It is believed that such an increase in body temperature is characteristic of lobar pneumonia, typhoid fever, viral infections(for example, the flu).

2. Laxative fever (relapsing). A constantly elevated body temperature is observed, but daily temperature fluctuations exceed 1 0 C. A similar increase in body temperature occurs with tuberculosis, purulent diseases (for example, with a pelvic abscess, gallbladder empyema, wound infection), as well as with malignant neoplasms.

By the way, fever with sharp fluctuations in body temperature (the range between morning and evening body temperature is more than 1 ° C), accompanied in most cases by chills, is commonly called septic(see also intermittent fever, hectic fever).

3. Intermittent fever (intermittent). Daily fluctuations, as in remitting, exceed 1 0 C, but here the morning minimum lies within the normal range. Moreover, elevated body temperature appears periodically, approximately at regular intervals (most often around noon or at night) for several hours. Intermittent fever is especially characteristic of malaria, and is also observed in cytomegalovirus infection, infectious mononucleosis and purulent infection (eg, cholangitis).

4. Wasting fever (hectic). In the mornings, as with intermittent, normal or even low body temperature is observed, but daily temperature fluctuations reach 3-5 0 C and are often accompanied by debilitating sweats. Such an increase in body temperature is characteristic of active pulmonary tuberculosis and septic diseases.

5. Reverse or perverted fever differs in that the morning body temperature is higher than the evening one, although from time to time there is still the usual slight evening temperature rise. Reverse fever occurs with tuberculosis (more often), sepsis, brucellosis.

6. Irregular or irregular fever manifests itself by alternating different types of fever and is accompanied by varied and irregular daily fluctuations. Irregular fever occurs in rheumatism, endocarditis, sepsis, tuberculosis.

Fever form

1. Wave-like fever characterized by a gradual rise in temperature over a period of time (persistent or remitting fever for several days) followed by a gradual decrease in temperature and a more or less long period of normal temperature, which gives the impression of a series of waves. The exact mechanism by which this unusual fever occurs is unknown. Often observed in brucellosis and lymphogranulomatosis.

2. Relapsing fever (recurrent) characterized by alternating periods of fever with periods of normal temperature. In the most typical form, it occurs with relapsing fever, malaria.

One-day or ephemeral fever: elevated body temperature lasts for several hours and does not recur. It occurs with mild infections, overheating in the sun, after blood transfusion, sometimes after intravenous administration of drugs.

The daily repetition of attacks - chills, fever, drop in temperature - in malaria is called daily fever.

Three-day fever - recurrence of attacks of malaria every other day.

Four-day fever - recurrence of attacks of malaria after 2 fever-free days.

Five-day paroxysmal fever (synonyms: Werner-His disease, trench or trench fever, paroxysmal rickettsiosis) is an acute infectious disease caused by rickettsia, carried by lice, and occurring in typical cases in a paroxysmal form with repeated four-, five-day attacks of fever, separated by several days in remission, or in the typhoid form, with many days of continuous fever.

Symptoms accompanying a fever

Fever is characterized not only by an increase in body temperature. Fever is accompanied by increased heart rate and respiration; arterial pressure often goes down; patients complain of feeling hot, thirsty, headache; the amount of urine excreted decreases. Fever promotes an increase in metabolism, and since, along with this, appetite is reduced, patients who are febrile for a long time often lose weight. Feverish patients note: myalgia, arthralgia, drowsiness. Most of them have chills and chilliness. With tremendous chills, severe fever, piloerection ("goosebumps") and trembling occur, the patient's teeth chatter. Activation of heat loss mechanisms leads to sweating. Mental status abnormalities, including delirium and seizures, are more common in very young, very old, or debilitated patients.

1. Tachycardia(cardiopalmus). The relationship between body temperature and pulse deserves great attention, because, other things being equal, it is fairly constant. Usually, with an increase in body temperature by 1 ° C, the heart rate increases by at least 8-12 beats per 1 minute. If, at a body temperature of 36 0 C, the pulse is, for example, 70 beats per minute, then a body temperature of 38 0 C will be accompanied by an increase in heart rate up to 90 beats per minute. The discrepancy between high body temperature and pulse rate in one direction or another is always subject to analysis, since in some diseases this is an important recognition sign (for example, fever in typhoid fever, on the contrary, is characterized by relative bradycardia).

2. Sweating. Sweating is one of the heat transfer mechanisms. Profuse sweating is observed with a decrease in temperature; in contrast, when the temperature rises, the skin is usually hot and dry. Sweating is not observed in all cases of fever; it is characteristic of purulent infection, infective endocarditis and some other diseases.

4. Herpes. Fever is often accompanied by the appearance of a herpetic rash, which is not surprising: 80-90% of the population is infected with the herpes virus, although clinical manifestations of the disease are observed in 1% of the population; Activation of the herpes virus occurs at the time of reduced immunity. Moreover, speaking of a fever, ordinary people often mean herpes by this word. In some types of fever, a herpetic rash is so common that its appearance is considered one of the diagnostic signs of the disease, for example, lobar pneumococcal pneumonia, meningococcal meningitis.

5. Febrile convulsionsaboutgi. Convulsions with fever occur in 5% of children aged 6 months to 5 years. The likelihood of developing a convulsive syndrome with fever depends not so much on the absolute level of the increase in body temperature, but on the rate of its rise. Typically, febrile convulsions do not last more than 15 minutes (average 2-5 minutes). In many cases, convulsions are observed at the onset of fever and usually resolve on their own.

You can associate convulsive syndrome with fever if:

the age of the child does not exceed 5 years;

there are no diseases that can cause seizures (for example, meningitis);

convulsions were not observed in the absence of fever.

First of all, in a child with febrile seizures, meningitis should be considered (lumbar puncture is indicated if the clinical picture is appropriate). Calcium levels are measured to rule out spasmophilia in infants. If convulsions lasted more than 15 minutes, it is advisable to perform electroencephalography to rule out epilepsy.

6. Change in urinalysis. With kidney disease, leukocytes, cylinders, bacteria can be detected in the urine.

Diagnostics

In the case of acute fever, it is desirable, on the one hand, to avoid unnecessary diagnostic tests and unnecessary therapy for diseases that can end in spontaneous recovery. On the other hand, it must be remembered that under the mask of a banal respiratory infection, a serious pathology (for example, diphtheria, endemic infections, zoonoses, etc.) can be hidden, which must be recognized as early as possible. If an increase in temperature is accompanied by characteristic complaints and / or objective symptoms, then this allows you to immediately navigate the diagnosis of the patient.

The clinical picture should be carefully evaluated. They study in detail the anamnesis, the patient's life history, his trips, heredity. Next, a detailed functional examination of the patient is carried out, repeating it. They perform laboratory tests, including a clinical blood test with the necessary detail (plasmocytes, toxic granularity, etc.), as well as a study of pathological fluid (pleural, articular). Other tests: ESR, urinalysis, determination of the functional activity of the liver, blood cultures for sterility, urine, sputum and feces (for microflora). Special research methods include X-ray, MRI, CT (to detect abscesses), radionuclide studies. If non-invasive research methods do not allow making a diagnosis, a biopsy of the organ tissue is performed, bone marrow puncture is advisable in patients with anemia.

But often, especially on the first day of illness, it is impossible to establish the cause of the fever. Then the basis for decision-making is the patient's state of health before fever and disease dynamics.

1. Acute fever in the background of full health

When a fever occurs against the background of full health, especially in a young or middle-aged person, in most cases it is possible to assume an acute respiratory viral infection (ARVI) with spontaneous recovery within 5-10 days. When making a diagnosis of ARVI, it should be borne in mind that with an infectious fever, catarrhal symptoms of varying severity are always observed. In most cases, no tests (other than daily temperature measurements) are required. When re-examined after 2-3 days, the following situations are possible: improvement in well-being, decrease in temperature. The appearance of new signs, such as skin rashes, plaque in the throat, wheezing in the lungs, jaundice, etc., which will lead to a specific diagnosis and treatment. Deterioration / no change. In some patients, the temperature remains high enough or worsens general state. In these situations, repeated, more in-depth questioning and additional research are required to search for diseases with exogenous or endogenous pyrogens: infections (including focal), inflammatory or tumor processes.

2. Acute fever on a modified background

In the case of an increase in temperature against the background of an existing pathology or a serious condition of the patient, the possibility of self-healing is low. An examination is immediately prescribed (the diagnostic minimum includes general blood and urine tests, X-rays of organs chest). Such patients are also subject to more regular, often daily monitoring, during which indications for hospitalization are determined. Main options: Patient with a chronic disease. Fever may be associated primarily with a simple exacerbation of the disease, if it is of an infectious and inflammatory nature, such as bronchitis, cholecystitis, pyelonephritis, rheumatism, etc. In these cases, a purposeful additional examination is indicated. Patients with reduced immunological reactivity. For example, those suffering from oncohematological diseases, HIV infection, or receiving glucocorticosteroids (prednisolone more than 20 mg / day) or immunosuppressants for any reason. The appearance of fever may be due to the development of an opportunistic infection. Patients who have recently undergone invasive diagnostic tests or therapeutic procedures. Fever may reflect the development of infectious complications after examination/treatment (abscess, thrombophlebitis, bacterial endocarditis). There is also an increased risk of infection in drug addicts intravenous administration drugs.

3. Acute fever in patients over 60 years of age

Acute fever in the elderly and senile age is always a serious situation, because due to the decrease in functional reserves in such patients, acute disorders can quickly develop under the influence of fever, for example, delirium, heart and respiratory failure, dehydration. Therefore, such patients require immediate laboratory and instrumental examination and determination of indications for hospitalization. One more important circumstance should be taken into account: at this age, asymptomatic and atypical clinical manifestations are possible. In most cases, fever in the elderly has an infectious etiology. The main causes of infectious and inflammatory processes in the elderly: Acute pneumonia is the most common cause of fever in the elderly (50-70% of cases). Fever, even with extensive pneumonia, may be small, auscultatory signs of pneumonia may not be expressed, but will be in the foreground. general symptoms(weakness, shortness of breath). Therefore, with any obscure fever, an x-ray of the lungs is indicated - this is the law ( pneumonia is a friend of the elderly). When making a diagnosis, the presence of an intoxication syndrome (fever, weakness, sweating, cephalgia), impaired broncho-drainage function, auscultatory and radiological changes are taken into account. The range of differential diagnosis includes the possibility of pulmonary tuberculosis, which is often found in geriatric practice. Pyelonephritis is usually manifested by fever, dysuria, and back pain; in the general analysis of urine, bacteriuria and leukocyturia are detected; Ultrasound reveals changes in the pelvicalyceal system. The diagnosis is confirmed with bacteriological examination urine. The occurrence of pyelonephritis is most likely in the presence of risk factors: female sex, catheterization Bladder, obstruction urinary tract (urolithiasis disease, prostate adenoma). Acute cholecystitis can be suspected when there is a combination of fever with chills, pain in the right hypochondrium, jaundice, especially in patients with already known chronic gallbladder disease.

Other, less common causes of fever in the elderly and senile age include herpes zoster, erysipelas, meningoencephalitis, gout, polymyalgia rheumatica and, of course, SARS, especially during the epidemic period.

4. Prolonged fever of unknown origin

The conclusion "fever of unknown origin" is valid in cases where the increase in body temperature above 38 ° C lasts more than 2 weeks, and the cause of the fever remains unclear after routine studies. In the international classification of diseases of the 10th revision, fever of unknown origin has its own R50 code in the "Symptoms and signs" section, which is quite reasonable, since it is hardly advisable to raise a symptom to a nosological form. According to many clinicians, the ability to understand the causes of prolonged fever of unknown origin is the touchstone of the diagnostic abilities of a doctor. However, in some cases it is generally impossible to identify difficult-to-diagnose diseases. Among febrile patients who were initially diagnosed with "fever of unknown origin", according to various authors, from 5 to 21% of such patients account for the proportion of cases not fully deciphered. Diagnosis of fever of unknown origin should begin with an assessment of the social, epidemiological and clinical characteristics of the patient. To avoid mistakes, you need to get answers to 2 questions: What kind of person is this patient (social status, profession, psychological portrait)? Why did the disease manifest itself right now (or why did it take such a form)?

1. A carefully taken history is of paramount importance. It is necessary to collect all available information about the patient: information about previous diseases (especially tuberculosis and valvular heart disease), surgical interventions, taking any medications, working and living conditions (travel, personal hobbies, contacts with animals).

2. Conduct a thorough physical examination and perform routine tests (CBC, urinalysis, biochemistry, Wassermann test, ECG, chest X-ray), including blood and urine cultures.

3. Think about possible reasons fever of unknown origin in a particular patient and study the list of diseases manifested by prolonged fever (see list). According to various authors, the “big three” is at the heart of prolonged fever of unknown origin in 70%: 1. infections - 35%, 2. malignant tumors - 20%, 3. systemic diseases of the connective tissue - 15%. Another 15-20% is due to other diseases, and in about 10-15% of cases, the cause of fever of unknown origin remains unknown.

4. Form a diagnostic hypothesis. Based on the data obtained, it is necessary to try to find a "leading thread" and, in accordance with the accepted hypothesis, appoint certain additional studies. It must be remembered that for any diagnostic problem (including fever of unknown origin), first of all, you need to look for common and common, and not some rare and exotic diseases.

5. If you get confused, go back to the beginning. If the formed diagnostic hypothesis turns out to be untenable or new assumptions arise about the causes of fever of unknown origin, it is very important to re-question the patient and examine him, re-examine the medical records. Conduct additional laboratory tests (from the category of routine) and form a new diagnostic hypothesis.

5. Prolonged subfebrile condition

Subfebrile body temperature is understood as its fluctuations from 37 to 38 ° C. long subfebrile temperature occupies a special place in therapeutic practice. Patients in whom prolonged subfebrile condition is the dominant complaint are encountered quite often at the appointment. To find out the cause of low-grade fever, such patients are subjected to various studies, they are given a variety of diagnoses and prescribed (often unnecessary) treatment.

In 70-80% of cases, prolonged subfebrile condition occurs in young women with asthenia phenomena. This is due to the physiological female body, ease of infection of the urogenital system, as well as a high frequency of psycho-vegetative disorders. It must be borne in mind that prolonged subfebrile condition is much less likely to be a manifestation of any organic disease, in contrast to prolonged fever with a temperature above 38 ° C. In most cases, prolonged subfebrile temperature reflects a banal autonomic dysfunction. Conventionally, the causes of prolonged subfebrile condition can be divided into two large groups: infectious and non-infectious.

Infectious subfebrile condition. Subfebrile temperature always causes suspicion of an infectious disease. Tuberculosis. With unclear subfebrile condition, tuberculosis must first be excluded. In most cases, this is not easy to do. From the anamnesis are essential: the presence of direct and prolonged contact with a patient with any form of tuberculosis. The most significant is being in the same place with a patient with an open form of tuberculosis: an office, apartment, stairwell or entrance of the house where the patient with bacterial excretion lives, as well as a group of nearby houses united by a common courtyard. The presence in the anamnesis of previously transferred tuberculosis (regardless of localization) or the presence of residual changes in the lungs (presumably tuberculous etiology), previously detected during prophylactic fluorography. Any disease with ineffective treatment within the last three months. Complaints (symptoms) suspicious of tuberculosis include: the presence of a syndrome of general intoxication - prolonged subfebrile condition, general unmotivated weakness, fatigue, sweating, loss of appetite, weight loss. If pulmonary tuberculosis is suspected - chronic cough (lasting more than 3 weeks), hemoptysis, shortness of breath, chest pain. If extrapulmonary tuberculosis is suspected, complaints about a dysfunction of the affected organ, with no signs of recovery against the background of ongoing therapy. Focal infection. Many authors believe that prolonged subfebrile temperature may be due to the existence of chronic foci of infection. However, in most cases, chronic foci of infection (dental granuloma, sinusitis, tonsillitis, cholecystitis, prostatitis, adnexitis, etc.), as a rule, are not accompanied by fever and do not cause changes in the peripheral blood. It is possible to prove the causal role of the focus of chronic infection only when the sanitation of the focus (for example, tonsillectomy) leads to the rapid disappearance of the previously existing subfebrile condition. Subfebrile temperature is a constant sign of chronic toxoplasmosis in 90% of patients. In chronic brucellosis, subfebrile condition is also the predominant type of fever. Acute rheumatic fever (systemic inflammatory disease connective tissue with involvement in the pathological process of the heart and joints, caused by group A beta-hemolytic streptococcus and occurring in genetically predisposed people) often occurs only with subfebrile body temperature (especially with II degree of activity of the rheumatic process). Subfebrile condition may appear after an infectious disease ("temperature tail"), as a reflection of the syndrome of post-viral asthenia. In this case, the subfebrile temperature is benign, is not accompanied by changes in the analyzes and disappears on its own, usually within 2 months (sometimes the "temperature tail" can last up to 6 months). But in the case of typhoid fever, prolonged subfebrile condition that occurs after a decrease in high body temperature is a sign of incomplete recovery and is accompanied by persistent adynamia, non-decreasing hepato-splenomegaly and persistent aneosinophilia.

6 Traveler Fever

The most dangerous diseases: malaria (South Africa; Central, Southwest and Southeast Asia; Central and South America), typhoid fever, Japanese encephalitis (Japan, China, India, South and North Korea, Vietnam, the Far East and Primorsky Krai Russia), meningococcal infection(the incidence is common in all countries, especially high in some African countries (Chad, Upper Volta, Nigeria, Sudan), where it is 40-50 times higher than in Europe), melioidosis (Southeast Asia, the Caribbean and North Australia), amoebic liver abscess (the prevalence of amoebiasis is Central and South America, South Africa, Europe and North America, the Caucasus and the Central Asian republics of the former USSR), HIV infection.

Possible causes: cholangitis, infective endocarditis, acute pneumonia, legionnaires' disease, histoplasmosis (widely distributed in Africa and America, found in Europe and Asia, isolated cases are described in Russia), yellow fever (South America (Bolivia, Brazil, Colombia, Peru , Ecuador, etc.), Africa (Angola, Guinea, Guinea-Bissau, Zambia, Kenya, Nigeria, Senegal, Somalia, Sudan, Sierra Leone, Ethiopia, etc.), Lyme disease (tick-borne borreliosis), Dengue fever (central and South Asia (Azerbaijan, Armenia, Afghanistan, Bangladesh, Georgia, Iran, India, Kazakhstan, Pakistan, Turkmenistan, Tajikistan, Uzbekistan), Southeast Asia (Brunei, Indochina, Indonesia, Singapore, Thailand, Philippines), Oceania, Africa , Caribbean Sea (Bahamas, Guadeloupe, Haiti, Cuba, Jamaica) Not found in Russia (only imported cases), Rift Valley fever, Lassa fever (Africa (Nigeria, Sierra Leone, Liberia, Ivory Coast, Guinea, Mozambique , Senegal, etc.)), Ross river fever, p Rocky Mountain puffiness (USA, Canada, Mexico, Panama, Colombia, Brazil), sleeping sickness (African trypanosomiasis), schistosomiasis (Africa, South America, Southeast Asia), leishmaniasis (Central America (Guatemala, Honduras, Mexico, Nicaragua) , Panama), South America, Central and South Asia (Azerbaijan, Armenia, Afghanistan, Bangladesh, Georgia, Iran, India, Kazakhstan, Pakistan, Turkmenistan, Tajikistan, Uzbekistan), Southwest Asia (United Arab Emirates, Bahrain, Israel, Iraq , Jordan, Cyprus, Kuwait, Syria, Turkey, etc.), Africa (Kenya, Uganda, Chad, Somalia, Sudan, Ethiopia, etc.), Marseille fever (Countries of the Mediterranean and Caspian basins, some countries of Central and South Africa , the southern coast of Crimea and the Black Sea coast of the Caucasus), Pappatachi fever (Tropical and subtropical countries, the Caucasus and the Central Asian republics of the former USSR), Tsutsugamushi fever (Japan, East and Southeast Asia, Primorsky and Khabarovsk Territories of Russia), tick rickettsiosis howling North Asian (tick-borne typhus - Siberia and the Far East of Russia, some areas of Northern Kazakhstan, Mongolia, Armenia), relapsing fever (endemic tick - Central Africa, USA, Central Asia, the Caucasus and the Central Asian republics of the former USSR, severe acute respiratory syndrome (South - East Asia - Indonesia, Philippines, Singapore, Thailand, Vietnam, China and Canada).

Mandatory examinations in case of fever upon return from a foreign trip include:

General analysis blood

Examination of a thick drop and a smear of blood (malaria)

Blood cultures (infective endocarditis, typhoid fever, etc.)

Urinalysis and urine culture

Biochemical blood test (liver tests, etc.)

Wasserman reaction

Chest x-ray

Stool microscopy and stool culture.

7. hospital fever

Hospital (nosocomial) fever, which occurs during the patient's stay in the hospital, is observed in approximately 10-30% of patients, and one in three of them die. Hospital fever exacerbates the course of the underlying disease and increases mortality by 4 times compared with patients suffering from the same pathology, not complicated by fever. The clinical condition of a particular patient dictates the scope of the initial examination and the principles of treatment of fever. The following main clinical conditions accompanied by hospital fever. Noninfectious fever: due to acute illness internal organs(acute myocardial infarction and Dressler's syndrome, acute pancreatitis, perforated stomach ulcer, mesenteric (mesenteric) ischemia and intestinal infarction, acute deep vein thrombophlebitis, thyrotoxic crisis, etc.); associated with medical interventions: hemodialysis, bronchoscopy, blood transfusion, drug fever, postoperative non-infectious fever. Infectious fever: pneumonia, infection urinary tract(urosepsis), sepsis due to catheterization, wound postoperative infection, sinusitis, endocarditis, pericarditis, aneurysm of fungal origin (mycotic aneurysm), disseminated candidiasis, cholecystitis, intra-abdominal abscesses, bacterial translocation of the intestine, meningitis, etc.

8. Fever simulation

False temperature increase can depend on the thermometer itself, when it does not meet the standard, which is extremely rare. Fever is more common.

Simulation is possible, both for the purpose of depicting a feverish state (for example, by rubbing the reservoir of a mercury thermometer or preheating it), and for the purpose of hiding the temperature (when the patient holds the thermometer so that it does not heat up). According to various publications, the percentage of febrile state simulation is insignificant and ranges from 2 to 6 percent of the total number of patients with elevated body temperature.

Fever is suspected in the following cases:

• the skin has a touch normal temperature and there are no symptoms accompanying fever, such as tachycardia, redness of the skin;
• too high temperature is observed (from 41 0 C and above) or daily temperature fluctuations are atypical.

If fever is to be simulated, the following is recommended:

Compare the data obtained with the determination of body temperature by touch and with other manifestations of fever, in particular, with the pulse rate.

In the presence of a medical worker and with different thermometers, measure the temperature in both armpits and be sure to rectum.

Measure the temperature of freshly passed urine.

All measures should be explained to the patient by the need to clarify the nature of the temperature, without offending him with suspicion of a simulation, especially since it may not be confirmed.