Suspected nocardiosis in an immunosuppressed patient: a case report highlighting diagnostic challenges and management strategies

Abstract

Nocardiosis is a rare but potentially fatal opportunistic infection caused by Nocardia species, predominantly affecting immunocompromised individuals. This case report details the clinical course, diagnostic workup, and management of a 63-year-old female with a history of renal transplantation. Initial investigations, including imaging studies, revealed multiple cavitary pulmonary nodules and a solitary brain lesion, raising concerns for disseminated infection. The diagnostic challenge was compounded by the broad differential diagnosis in this patient population, including fungal, mycobacterial, and other opportunistic infections. Empirical antimicrobial therapy was initiated, and subsequent microbiological confirmation of Nocardia asteroides from bronchoalveolar lavage specimens established the diagnosis. Despite initial therapeutic response, the patient developed worsening neurological symptoms indicative of CNS involvement, necessitating prolonged treatment with a combination of trimethoprim-sulfamethoxazole and imipenem. This report underscores the importance of early recognition, comprehensive diagnostic evaluation, and individualized therapeutic approaches in managing suspected nocardiosis in immunocompromised patients. Furthermore, it discusses the diagnostic pitfalls, highlights the need for a high index of suspicion, and reviews current therapeutic recommendations for both pulmonary and disseminated nocardiosis, providing a valuable reference for clinicians managing similar cases.