Pneumocystis Pneumonia : Clinical Features

Pneumocystis pneumonia was known before the onset of HIV epidemic. It was primarily seen in malnourished children and, sometimes, as an opportunistic infection in children undergoing chemotherapy for childhood leukemias. It became a common cause of pneumonia during HIV epidemic. However, with the availability of effective treatments for AIDS, pneumocystis pneumonia is more likely to be encountered in other groups at risk such as those receiving long-term steroid therapy or immunosuppression, including organ transplant recipients, those with collagen vascular diseases, patients undergoing chemotherapy for hematopoietic malignancies, and chronic obstructive pulmonary disease.

Patients present with fever, cough, and dyspnea. The treatment is usually with trimethoprim-sulphamethoxazole. This PAS-stained section from lung highlights the classic foamy alveolar casts from an AIDS patient with pneumocystis pneumonia.