Localized Pneumocystis jirovecii pneumonia in a malnourished, non-HIV-infected man in the absence of any established or diagnosed immunosuppressive condition: a case report.

Background: Pneumocystis jirovecii infection is an opportunistic infection that mostly affects patients with immunosuppressive conditions like human immunodeficiency virus (HIV) infection or medications, like corticosteroids. This study reports a rare case of Pneumocystis Jiroveci infection in a relatively immunocompetent patient which presented with uncommon radiological findings.

Case presentation: A 46-year-old man with a malnourished appearance and a history of opium dependence presented with dry cough, dyspnea, and weight loss to the hospital. There was no evidence of an immunocompromised condition or use of any immunosuppressive medication in the history of the patient. A lung high-resolution computed tomography (HRCT) scan revealed a crazy-paving appearance and localized infiltration. Methenamine silver staining and the histopathological findings in the transbronchial lung biopsy confirmed the diagnosis of PJP. Antibiotics and bronchodilators were administrated and the patient was discharged after 6 days of hospitalization. HIV testing and immunoglobulin levels were normal in the hospital course as well as his follow-up visits. After a 2-month follow-up, the patient was in good condition despite of mild remaining infiltration in his lung.

Conclusions: PJP typically affects HIV-infected patients, but due to excessive use of immunosuppressive medications, its prevalence is increasing in non-HIV-infected patients. Malnutrition may predispose the patients to PJP, even in the absence of immunosuppressive conditions.