[A rare but increasing aetiology of febrile dyspnea in the elderly].

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infectious disease well described in patients living with HIV (PLHIV) but that can occur in other immunosuppressed patients. Currently, its incidence decreases in PLHIV but increases in non-HIV immunosuppressed patients, particularly in case of hematological diseases. Thus, in elderly, the diagnosis of PJP should be evoked in case of subacute pneumonia rapidly evolving to an acute respiratory distress, with or without interstitial pneumonia at chest radiography, and a context of immunosuppression.