Upper lobe relapse of Pneumocystis carinii pneumonia during aerosolized pentamidine prophylaxis.

A patient with a history of Pneumocystis carinii pneumonia (PCP) inhaled aerosolized pentamidine (AP) for secondary prophylaxis of PCP. Nine months after the first PCP episode he presented with pulmonary upper-lobe infiltrations demonstrated by chest x-ray, and bronchoalveolar lavage confirmed the diagnosis of PCP. The clinical course and possible explanations for this unusual form of PCP are presented. The case emphasizes the importance of clinical controls for early diagnosis of relapse of PCP in patients inhaling aerosolized pentamidine. Monitoring of serum lactate dehydrogenase levels appeared to be important in the follow-up of the patient described.