Fever is one of the oldest clinical indicators of disease in the mammalian host as well as one of the most common reasons for medical consultations worldwide .
Fever is controlled increase in body temperature above the normal hypothalamic set point. Our normal body temperature is 36.6 to 37.2 °C regulated by thermosensitive neurons in the hypothalamus. Oral temperature is the reference and fever is diagnosed when it exceeds 37.8°C rather than our skin temperature and rectal (eardrum) temperature which is about 37 °C and 37.5 °C respectively. Hypyrexia is defined by temperature above 40°C.
Normal and Febrile Body Temperature Ranges (rectal temperatures):
1. Infectious Causes 2. Non- Infectious causes
Patterns of Fever
Guidelines for Investigation of Fever
1. If Fever is recorded by experienced, trained and reliable parent then treat as febrile neonate means infant having fever.
2. In false cases, remove excess covering and temperature should be taken in every 15-30 minutes.
3. Blood, Urine, CSF should be cultured
4. CSF study includes cell counts, Glucose, protein levels, gram stain and culture.
5. HSV & Enterovirus Polymerase Chain Reaction.
6. Stool culture and Chest Radiograph.
1. For ill appearing febrile infants Ceftriaxone or Cefotaxime in prescribed dosage level plus Ampicillin to cover L. monocytogenes & Enterococcus.
2. For meningitis- Vanomycin for Pencillin resistant S. pneumonia.
3. Acyclovir for HSV infection.
4. For infants with fever who appear generally well having total WBC Count of 5000-15000 cell/ml and normal urine analysis are unlikely to have serious Bacterial infection.
However, fever is not without its ill-effects, especially in cases of very high fevers, or when high fever is associated with co-morbidities such as severe sepsis, and pre-existing cardiopulmonary disease. It has been suggested that fever is necessary for evolutionary survival of species by accelerating the recovery of infected individuals with localised or mild to moderately severe systemic infections via immune system stimulation and formation of antibodies against foreign particles while hastening the demise of hopelessly infected individuals, who pose a threat of epidemic disease to the species. Therefore for some, fever may be a blessing, while for others a curse.