Cutaneous Talaromyces marneffei Infection in an Immunocompetent Adolescent: A Case Report.

Talaromyces marneffei (TM) infection is a rare but potentially fatal deep fungal disease that typically affects immunocompromised individuals in endemic regions. However, an increasing number of cases have been reported in HIV-negative, immunocompetent patients without classical risk factors. We report the case of a 15-year-old girl residing in urban southern China who presented with chronic cutaneous plaques and cervical lymphadenopathy, initially misdiagnosed as tuberculous lymphadenitis. Despite one year of anti-tuberculosis therapy, her condition worsened and liver dysfunction developed. Subsequent skin biopsy, fungal culture, and metagenomic next-generation sequencing (mNGS) confirmed localized cutaneous TM infection. The patient responded well to oral itraconazole, and lesions resolved after four months of treatment, with no recurrence during an 18-month follow-up. This case highlights the importance of considering deep fungal infections in the differential diagnosis of chronic granulomatous skin lesions, even in immunocompetent hosts, and emphasizes the diagnostic utility of mNGS in atypical presentations.