Pyrexia of unknown origin: Aetiologic Frequency in a Tertiary Care Hospital

Background: The aetiology of fever varies with age, sex, and geographical location. The most common causes fall in three main groups namely infections, collagen vascular diseases and malignancies. This study was conducted to know the frequency of different diseases causing pyrexia of unknown origin in patients admitted to a tertiary care hospital.Material Methods: This was a descriptive study of 100 patients with fever admitted to Medical Unit, Khyber Teaching Hospital Peshawar from March 2008 to March 2009. A detailed history and clinical examination was performed on admission and then periodically during the patient stay in the hospital. Based on the history and clinical examination, investigation plan was made. The preliminary laboratory investigations e.g. complete blood count, urinalysis, blood film examination and x-ray chest, were carried out. In every patient an attempt was made to isolate a causative micro-organism through cultures.Results: Out of 100 patients 40 were males and 60 females. We were successful only in 83% of the cases to determine the cause. Majority (57%) had infective aetiology of which tuberculosis was at the top of the list (32%). The other diagnoses included neoplasms (10%), collagen vascular diseases (12%) and miscellaneous (3%).Conclusion: Pyrexia of unknown origin is predominantly caused by infections led by tuberculosis and followed by typhoid fever, malaria and infective endocarditis. Collagen vascular diseases and neoplasms are next to infection. A significant number remains undiagnosed