Erythema nodosum associated with sporotrichosis

Case 1 A 34‐year‐old woman had ulcerated lesion 2 cm in diameter on the right leg of 2 months’ evolution. She also presented painful erythematous nodules on lower limbs accompanied by arthralgia appearing 1 month after the initial lesion ( Figure 1a). The patient reported having been scratched on the right leg by a cat with sporotrichosis 15 days before the initial symptoms. Examination of the ulcerated lesion showed growth of Sporothrix schenckii , and histological investigation of one nodule showed a mononuclear inflammatory infiltrate in the hypodermis with a predominantly septal distribution, negative upon culture for fungi ( Figure 1b). Radiographic examination of left ankle showed increased soft tissue, while other ancillary tests were normal. The patient was treated with itraconazole 100 mg/day for 4 months, with regression of Erythema nodosum (EN) on day 20. Figure 1 (a) Ulcerated lesions on right calf and erythematous nodules on lower limbs. (b) Histopathology of one lower limbs nodule, displaying small granuloma in the subcutaneous cellular tissue (HE, 4 ×)Case 2 A 25‐year‐old woman presented to our facility for evaluation of an ulcerated lesion measuring 3 cm on her left wrist accompanied of ascending subcutaneous nodules on her lower limbs. She reported having been scratched on the site of a subsequent lesion 10 days previously by a cat with sporotrichosis. Culture of ulcerated lesions produced S. schenckii . The patient was placed on itraconazole 100 mg/day. One week after initiating treatment, she suffered a second scratch, which was followed, 7 days later, by nodular lesions located on the lower limbs accompanied by arthralgia and fever. Histopathology showed a predominantly hypodermic perivascular mononuclear inflammatory infiltrate with a septal distribution, forming small granulomas and producing a negative culture ( Figure 2b). Radiography of ankles showed increased soft tissue. The treatment was maintained, with regression of EN after 50 days and total regression of lesions by the third month. 2(a) Ulcerated lesion with infiltrated borders on left wrist and erythematous nodules on lower limbs. (b) Histopathology of one lower limbs nodule, showing granulomatous tissue reaction in hypodermis (HE, 20 ×)Case 3 A 12‐year‐old boy was admitted,with an ulcerated 2 cm lesion on the left foot with slightly infiltrated borders and secretion, accompanied by painful groin adenomegaly. Physical examination also revealed a recent scar measuring 1.5 cm on the left knee. He denied trauma but reported household contact with 11 cats with sporotrichosis. Upon his return visit 40 days later, the patient presented painful erythematous nodules on his knees and thighs, plus knees and ankles edema with arthralgia ( Figure 3a). Culture of ulcerated lesion, by now nearly healed, showed S. schenckii . Histopathological examination of a nodule showed septal and lobular hypodermic infiltrate with formation of granulomas and negative fungal culture ( Figure 3b). He was treated with itraconazole 100 mg/day for 3 months, with regression of EN and arthralgia on day 20 of treatment. 3(a) Cicatricial lesion and erythematous nodules on left knee (b) with biopsy showing significant inflammatory infiltrate in dermis and hypodermis, with giant cells (HE, 20 ×)