Pyrexia of unknown origin : Dr. R.N. Sarma 


Fever where the aetiology could not be ascertained remains an important clinical problems in spite of overwhelming development of scientific information, newer diagnostic techniques and high tech investigational facilities PUO can be a challenge, can be a head ache and at times nightmare. Modern textbooks mention
200 and odd causes of PUO. The approach should be meticulous stepwise and thorough. We should not overlook hidden facts in history. Assessment should include head to foot examination of the patient everyday ordering the approptiate and releavant investigations (including hightech) that are needed. Since PUO can be due to multiple causes elaborate investigations may be needed PUO can be due to hidden infections (no localizing symptoms)
{can be viral, bacterial, fungal mycobacterial}, malignancies Connective tissue diseases, arteritis or drugs. Rarely fever can be factitious also.

History should take into account the geographic area of the patient, events in the pastailments in the family, places the patient has visited and surgical implants if any. All are important in appropriate circumstances. Physical examination should focus on general examination first followed by system wise examination This should be done every day Newer findings can crop up at anytime which will throw more light on the aetiology. There is no role for taking things for granted.Cases of fever of undetermined aetiology may declare the dignosis several days after admission Certain investigations are to be repeated Several X rays normal previously can declare an abnormality in a subsequent X ray. In the diagnosois of infections microbilologial support is crucial. Unfortunately the patient would have been subjected to multiple antibiotics which will render subsequent cultures negative. In analyzing the causes of PUO close collaboration with microbiologist, imageologist ,cardiologist, rheumatologist, pulmonologist and all other supportive departments may become essential depending on aetiology. A patient may be admitted with fever and the original fever subsides and another fever raises its head (eg a gluteal abscess appearing subsequently, and in indwelling catheter getting infected). Tuberculosis still remains an important cause of PUO in our country. In the era of replacement surgery their getting infected and producing PUO should be considered strongly. Underlying HIV should not escape our attention.

In short PUO requires meticulous thorough evalution from the scratch concentrating on detailed history. Physical findings tailored investigations collaborating with colleagues and other disciplines.