Fever is the condition which oral body temperature more than 37,4oC. The average normal oral body temperature is 36,7oC (range 36-37,4oC). Fever is the symptom that is most readily recognized as a sign of illness and brings the patients quickly go to doctor.
Diseases or conditions that causes of fever include: many infectious (such as Meningitis, Urinary tract infection, Sub acute bacterial endocarditis, Septicemia, Pneumonia, Typhoid and Paratyphoid fever, Gall bladder infection, Diverticulitis, Infectious disease associated with travel, Malaria, Viral disease, Infective hepatitis, Infectious mononucleosis), inflammatory disease, neoplastic or malignant disease (such as Leukemia and Hodgkin’s disease) and hypersensitivity reactions or autoimmune disorders (such as Lupus erythematous, Rheumatoid arthritis), Dehydration, Medication and Venous thrombosis.
Examination is proposed to find causes of fever and where the site of problem is obvious. More extensive examination of the chest, abdomen, central nerve system (CNS), stiffness will be needed noting in particular if any skin rash is present.
- If the physical examinations provide strong indication of an infectious process, laboratory studies can be used selectively to confirm or refute the clinical diagnosis.
- Initial investigations may not be necessary if the cause is obvious e.g., Upper Respiratory Tract Infection (URTI). However, if pneumonia is a possibility then a chest X-ray and complete blood count would be necessary.
- Blood film for malaria parasite may be indicated based on the history.
- In other patients, more extensive tests are needed to establish the diagnosis when the cause of fever remains unknown. The approach to diagnosis would include the following:
- Complete blood count, differential total white and sedimentation rate.
- Urinalysis, Isolated hematuria may be a clue to underlying glomerular disease or urinary tract malignancy.
- Chest X-ray may detect infiltrates effusions or masses even in absence of abnormalities on physical examination; a KUB and upright abdominal films can disclose air fluid level in the bowel; ultrasound or CAT study may be needed if there is suspicion of a mass lesion, such as an abscess or a tumor.
- Blood chemistry, liver function tests are useful in helping to defines obscure sources of fever. For example transaminase elevation suggests hepatitis, and isolated rises in alkaline phospatase point to infiltration of the liver.
- Blood culture, if the patient has a heart murmur or prosthetic heart valve or appears seriously ill.
- Serological tests, Widal and Weil Felix tests may help to confirm typhoid fever.
Initial Routine Management:
- Symptomatic relief of fever.
- Antibiotics if bacterial infection is thought likely.
- Advice on fluid intake.
- Advise further action to report back if fever does not settle in a day or two or there are new developments e.g., rash, patient becomes more ill.
- Ill patients are referred for admission.
Prevention of complications:
- The complications of fever likely to be seen in general practice are dehydration and febrile convulsions in childhood, and confusion states in the elderly. Old people also become easily dehydrated when febrile and ill.
- Dehydration could be prevented by maintaining an adequate fluid intake and most principles febrile convulsions prevention by control of the temperature.
Indication for referral:
- The ill patient.
- Clinically diagnosed serious conditions such as meningitis, pneumonia, cholecystitis, to name a few.
- The patient whose fever persists beyond a week and the cause is still uncertain.