Pulmonary nocardiosis in a patient with idiopathic CD4 T‐lymphocytopenia

Idiopathic CD4 T‐lymphocytopenia (ICL) is a rare immunodeficiency characterized by low CD4 T‐lymphocyte count, which usually manifests with opportunistic infections. Nocardia as an opportunistic pathogen infecting patients with this condition has rarely been reported. Here, we describe the case of a 46‐year‐old male who presented with lung mass and respiratory and systemic symptoms and was eventually diagnosed with pulmonary nocardiosis. A workup for predisposing immunodeficiencies suggested a picture of ICL. This case illustrates the importance of considering ICL as a possible predisposing condition when an otherwise healthy individual presents with pulmonary nocardiosis.