Unusual Cutaneous Manifestations of Nocardiosis: Clinical Insights from a Case Series

Background: Nocardiosis is an uncommon yet clinically significant infection caused by aerobic, Gram-positive, partially acid-fast filamentous bacteria of the genus Nocardia.Cutaneous nocardiosis is rare and often underdiagnosed because its clinical presentation frequently mimics bacterial, fungal, or mycobacterial infections.This overlap may lead to delayed diagnosis and inappropriate treatment.The disease can affect both immunocompetent and immunocompromised individuals and exhibits a broad spectrum of clinical manifestations.Methods: We report a case series of three patients presenting with unusual cutaneous manifestations of nocardiosis, emphasizing diagnostic challenges, microbiological findings, treatment strategies, and outcomes.The cases included: (i) a 22-day-old neonate with multifocal cervicofacial abscesses, (ii) a 47-year-old post-COVID female with a disseminated Nocardia farcinica infection presenting as an intramuscular thigh abscess, and (iii) a 42-year-old immunocompetent farmer with a primary cutaneous abscess over the upper back.Diagnosis was established through direct microscopy using Gram staining and modified Ziehl-Neelsen staining, followed by culture confirmation.Results: All cases demonstrated characteristic microbiological features of Nocardia species, including branching Gram-positive, partially acid-fast filaments and dry, chalky white colonies on culture.Management consisted of surgical drainage combined with prolonged antimicrobial therapy, primarily trimethoprim-sulfamethoxazole, with adjunctive agents such as imipenem or amikacin in severe or disseminated disease.All patients showed complete clinical resolution without recurrence on follow-up.Conclusion: This series underscores the diverse cutaneous presentations of nocardiosis across different age groups and immune statuses.Early recognition, timely microbiological diagnosis, and prolonged targeted therapy are critical to reducing morbidity and preventing dissemination or relapse.