Primary cutaneous mixed infection with Cryptococcus uniguttulatus and Mycobacterium tuberculosis

Cutaneous mixed infections involving multiple pathogens present significant diagnostic and therapeutic challenges. Here, we report the first documented case of concurrent cutaneous infection caused by Cryptococcus uniguttulatus and Mycobacterium tuberculosis in a 43-year-old male. Initial histopathological examination revealed fungal organisms, and subsequent culture identified C. uniguttulatus as the causative pathogen. Despite treatment with oral itraconazole and amphotericin B, complete resolution was not achieved. Further molecular diagnostic testing using real-time PCR and next-generation sequencing (NGS) revealed a concurrent M. tuberculosis infection. Following successful management of the cryptococcal infection, combination anti-M. tuberculosis therapy led to significant improvement of the cutaneous lesions. This case represents not only the first reported instance of cutaneous C. uniguttulatus infection but also the first documented case of mixed cutaneous infection involving both Cryptococcus and Mycobacterium species. This case underscores the importance of comprehensive diagnostic approaches, particularly molecular methods, in identifying complex infections that may be missed by conventional culture techniques. Additionally, it highlights the necessity of considering mixed infections in cases refractory to initial therapy, even in immunocompetent individuals.