Fever in children

Fever is a symptom, not a disease, and the single most common cause for paediatric visits. Despite various commonly held beliefs about what should be considered a fever, it is defined as a temperature of > 38º C rectally, > 37º C axillary or > 37,5º C orally, measured by a mercury or digital thermometer. Fever results from an increase in metabolic activity following an increase in hypothalamic thermoregulatory set point. The set point is elevated by prostaglandins which are synthesized in the brain under the influence of interlekuins and other inflammatory mediators set free during infections, autoimmune disease and malignancies. An increase in body temperature due to exogenous overheating with impairment or relative inability to emit heat from the body surface is usually termed hyperthermia. Fever is usually detected by touching the forehead, and is measured by a mercury or digital thermometer (rectally, axillary, orally), infrared thermometer (ear), or a thermosensitive ribbon (placed on the forehead). The interpretation of fever depends on the age of the child, the degree of elevation and accompanying symptoms. Any fever in an infant below the age of 2 months, or fever >40.0º C regardless of the age, should be immediately evaluated by a physician. Fever is lowered with antipyretics: acetaminophen and ibuprofen. Rapid transient decrease in fever can be achieved by tepid sponging or partial submersion in tepid water 29-32º C. Combining or alternating antipyretics lacks controlled scientific corroboration. Emphasis should be on adequate antipyretic dosage, good hydration, bed rest, light clothes and a light diet.