Chronic Thoracic Cutaneous Sporotrichosis in Women Without Typical Exposure: A Diagnostic Challenge Under Suspected Pyoderma Gangrenosum

Sporotrichosis is a cutaneous fungal infection caused by the Sporothrix complex, usually acquired through traumatic inoculation or contact with infected cats. Its clinical manifestations may mimic bacterial infections or inflammatory dermatoses, complicating diagnosis, especially in atypical locations and without clear epidemiological exposure. This report describes two unusual cases of chronic thoracic sporotrichosis in women with diabetes mellitus ‒ one associated with an insect bite and the other without any epidemiological contact with cats or animals. Two female patients, both with type 2 diabetes and irregular use of hypoglycemic agents, had chronic wounds on the anterior thoracic region for years, with intermittent discharge, local pain, and failure to heal. Both had received multiple topical and systemic antibiotic courses without clinical response. There was no history of local trauma or animal contact. Outpatient biopsies showed nonspecific chronic inflammation. Given the long evolution and lesion appearance, pyoderma gangrenosum was considered among the main hypotheses, raising the possibility of corticosteroid therapy. However, before starting immunosuppressants, further in-hospital investigation was performed with new biopsies and fungal culture, confirming cutaneous sporotrichosis due to Sporothrix spp. Both were treated with itraconazole, with progressive clinical response and lesion improvement. Thoracic presentation and absence of classic risk factors make these cases atypical. Diabetes mellitus may have contributed to chronicity and difficulty in spontaneous resolution. The recurrence of a similar clinical pattern in two different patients, with uncommon location and prolonged course, highlights the importance of considering sporotrichosis even without suggestive epidemiology, particularly in the setting of granulomatous-pattern biopsies and antibiotic treatment failure. Sporotrichosis should be considered in chronic, non-healing cutaneous lesions, especially when biopsies show a granulomatous pattern and there is failure of antibiotic therapy. In such cases, careful exclusion of fungal infections is essential before introducing immunosuppressants such as corticosteroids, which could significantly worsen the condition and delay appropriate treatment.