Systemic Pneumocystis carinii pneumonia prophylaxis with dapsone and pyrimethamine fails to protect against extrapulmonary pneumocystosis.

Extrapulmonary pneumocystosis is a feature of severe immunosuppression which earlier reports have suggested is limited to patients receiving either no prophylaxis or aerosolised pentamidine. We report a case of disseminated pneumocystosis which developed in an HIV positive homosexual man despite systemic primary Pneumocystis carinii pneumonia prophylaxis.