Subfebrile fever in a child

Subfebrile temperature in a child is determined when, when measured, the indicator fluctuates in the range from +37°C to +38°C.

It is this thermal state of the body - both in an adult and in a child - that is considered near-feverish and is often defined by doctors as subfebrile fever. For what reasons does subfebrile temperature occur in children?

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Causes of subfebrile temperature in children

An increase in temperature is a symptom, and a symptom of so many different diseases and pathological deviations from the norm that it is probably impossible to cover this topic in detail in one publication. But we will try to provide you with the most important information.

So, the simplest reason for subfebrile temperature in infants and children up to one and a half years is teething, which is accompanied by increased salivation and the baby's desire to put everything in his mouth - to rub the itchy gum. At the same time, the child is restless, eats poorly, and cries often.

Often, a child's subfebrile temperature during the day is associated with allergies, which an increasing percentage of children suffer from, or with a decrease in immunity, which is also typical in our time. And an increase in temperature in the evening can occur due to nervous tension or excessive physical activity of the child, since the metabolism in a growing child's body is unstable and has its own specifics.

Colds and acute respiratory viral infections, i.e. ARI or flu, are the most common cause of subfebrile temperature in children. And imagine, it is when the temperature rises that the production of endogenous interferon is “switched on” at full capacity – a special protein that not only prevents the virus from multiplying, but also raises all protective reserves of the body’s humoral immunity, including antibodies and phagocytes, to counterattack pathogens.

It should be emphasized: subfebrile temperature is a characteristic sign of most infectious diseases that children may have. These are tonsillitis, adenovirus infection, chickenpox, rubella, whooping cough, diphtheria, meningitis, infective endocarditis, tuberculosis. At the same time, diseases such as measles, scarlet fever and infectious mumps give a temperature above +38°C.

A child may have a subfebrile temperature due to the activation of persistent viruses that are constantly present in the body: herpes simplex virus type I and II (its calling card is a “cold sore” on the lips), herpes virus type VI (which causes roseola in children), and herpes virus type IV (Epstein-Barr virus), the causative agent of infectious mononucleosis.

Subfebrile temperature may be a consequence of inflammations, the foci of which are hidden in the child's body, and the processes themselves are sluggish, without pronounced symptoms. Latent inflammatory foci are formed in chronic forms of sinusitis, adnexitis, tonsillitis and focal pneumonia, as well as cholecystitis, cystitis and pyelonephritis. Moreover, with these diseases, there is a high probability of superimposing a secondary - bacterial - infection on the initial inflammation, and as a result, the thermometer constantly crosses the +37°C mark.

Invasive diseases (helminthiasis) and protozoan infections (toxoplasma and mycoplasma) should not be discounted. It should be taken into account that helminths (parasitic worms) can settle not only in the intestines (which is detected by the results of appropriate tests), but also in the lungs and liver...

An etiological connection is noted between subfebrile fever in children and such endocrine pathologies as hyperthyroidism (thyrotoxicosis) and diabetes mellitus, as well as with most autoimmune diseases of connective tissue and joints: systemic lupus erythematosus, systemic scleroderma and vasculitis, juvenile rheumatoid arthritis, etc.

A prolonged subfebrile temperature in a child should alert parents, as it may be a sign of an oncological disease (leukemia, lymphogranulomatosis, craniopharyngioma, etc.);

When listing the causes of subfebrile temperature in children, we cannot ignore the deficiency of vitamins B9 and B12. With their deficiency, the bone marrow produces less hemoglobin, and then it is more difficult for erythrocytes to supply oxygen to the cells of the brain, which leads to functional disorders of its parts, in particular, the thermoregulatory part of the diencephalon - the hypothalamus.

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It's all about the hypothalamus

By the way, pediatricians say that a long-term subfebrile temperature in a child may indicate a congenital or acquired problem with its regulation in hypothalamic (diencephalic) syndrome - a multifactorial pathology of the hypothalamus. American doctors call this pathology dysfunction of the hypothalamus, Western European doctors - hypothalamic disease.

The hypothalamus maintains the internal balance of the body (homeostasis); plays an important role in coordinating signals between the nervous and endocrine systems; controls body temperature, heart rate and blood pressure, feelings of hunger and thirst; through the hormones it produces, it regulates many hormonal and behavioral circadian rhythms of the body.

Hypothalamic disease can be caused by genetic disorders, brain injury (including birth injury), poor blood supply to the hypothalamic region of the brain, previous encephalitis or meningitis, prolonged malnutrition or eating disorders (anorexia or bulimia), increased radiation, brain tumor or physical damage to the brain during surgery, etc.

As a result of hypothalamic disease, numerous dysfunctions appear, including failures in thermoregulation, which leads to subfebrile temperature in children.

A subfebrile temperature detected in a child during the day, which does not respond to any antipyretic drugs, can be diagnosed as thermonurosis, which is especially common in adolescence and is associated by most pediatricians with a large-scale restructuring of the body and central nervous system that occurs during puberty.

Treatment of subfebrile temperature in children

The first and most important thing that parents need to keep in mind: treating subfebrile temperature in children - in the absence of any hints of a cold or flu - will not give a positive result if you do it yourself, that is, bypassing the most important stage of the fight against any disease - diagnosis. And for this, the child must be examined - with all the tests, ultrasound and magnetic resonance imaging of the internal organs and brain. Therefore, we strongly recommend not to delay contacting experienced medical specialists.

If you immediately start treating a cold with drugs that reduce temperature, this can only complicate the course of the disease. Doctors constantly remind that antipyretic drugs for viral infections should be taken at a temperature above +38°C, so as not to disrupt the process of the body's production of its own interferon. And in case of infectious diseases, naturally, you cannot do without antibiotics, which should only be prescribed by your doctor

In other cases, treatment of subfebrile temperature in children should be carried out in accordance with the algorithm of therapy of the identified disease - that is, eliminating the cause of its occurrence. Of course, if this is possible, since in the clinical practice of pediatricians and doctors of certain specializations there are many cases of so-called subfebrile temperature of unclear etiology. Such cases are usually considered to be a periodic increase in temperature to +38 ° C for at least 20 days, the causes of which cannot be established during a medical examination conducted in a hospital setting.

Considering the fact that subfebrile temperature in a child may be a manifestation of hypothalamic pathology, parents should consult a neurologist.