Sporotrichosis is a fungal infection caused by Sporothrix spp., typically presenting as an ulcerated lesion with nodular lymphangitis following traumatic inoculation into the skin. Previously associated with rural settings, it has become urbanized due to zoonotic transmission. A 79-year-old patient with non–insulin-dependent diabetes sustained trauma from plant material on the sole of the foot while walking on a beach five months prior to presentation. The patient reported contact with stray animals with skin lesions but denied bites or scratches. After the event, the wound progressed to an extensive, deep ulcer with tendon exposure, involving two-thirds of the left lower limb up to above the knee level, with bleeding, and associated with subcutaneous nodules that formed new peripheral ulcers throughout the leg. During this period, the patient was hospitalized at other facilities for broad-spectrum antibiotic therapy, with worsening of the wound. Itraconazole was administered without significant improvement. The patient was admitted to a referral hospital for diagnosis and follow-up. Swab specimens were collected for fungal culture and smear evaluation for other infectious agents, and a biopsy was performed for histopathological examination. Culture showed growth of Sporothrix spp. Smear analysis demonstrated acute inflammatory disease with an absolute predominance of polymorphonuclear cells. Histopathology revealed a superficial dermal interstitial and perivascular lymphohistiocytic infiltrate with scattered neutrophils. In the deep dermis, dermal fibrosis associated with an area of granulomatous reaction was noted. Treatment with amphotericin B lipid complex was instituted for 42 days, with gradual ulcer improvement and healing of satellite lesions. After hospital discharge, the patient continues outpatient treatment with itraconazole. This report highlights an atypical presentation of sporotrichosis as extensive subcutaneous dissemination in the affected limb, without the classic pattern of centripetal nodular lymphangitis. Microscopic analysis of the smear showed acute inflammation with predominance of polymorphonuclear cells, which explains the deep necrosis—an uncommon pathological feature. With the shift in epidemiological profile and increasing incidence of urban sporotrichosis, atypical forms have been observed, which complicates diagnosis and delays early treatment.
Weber et al. (Sun,) studied this question.