Sporotrichosis of the upper extremity

This article presents a case of a chronic, nonhealing thumb wound in a patient with diabetes mellitus. A 67-year-old right-hand-dominant man presented with progressive erythema and swelling of the right thumb several months after sustaining a paper cut along the eponychium. The patient had already completed an extensive laboratory evaluation, including bacterial and fungal cultures, as well as a punch biopsy that was inconclusive. In addition, the patient underwent several rounds of empiric antibiotic therapy without resolution of his symptoms. Despite these measures, the patient's thumb wound persisted and new lesions began to appear proximally along the forearm. Excisional biopsy of the lesions was ultimately required to obtain additional tissue for a pathologic analysis. Culture of the specimen on Saboraud dextrose agar revealed a definitive diagnosis of infection with Sporothrix schenkii. A subsequent course of oral antifungal therapy with itraconazole was well tolerated and resulted in disease regression. Early diagnosis of sporotrichosis is essential to prevent complications including septic arthritis, systemic infection, and death. This case illustrates the importance of maintaining a high index of suspicion for atypical infectious agents in patients with poor immune function.