Background: Fungal infections, especially in immunocompetent children are uncommon causes of fever of unknown origin.
Case characteristics: A 5-year-old boy with prolonged fever and no evidence of immunosuppression.
Observation: Ultrasound-guided retroperitoneal lymph node biopsy showed granulomas and intracytoplamic fungal yeasts; staining charactristics were suggestive of cryptococci. Clinical and radiological improvement was seen after treatment with amphoterecin-B.
Outcome: Disseminated fungal infection should be suspected as a cause of pyrexia of unknown origin after ruling out the commoner causes. Biopsy from enlarged lymph node or organomegaly may yield the diagnosis when non-invasive tests fail.