A woman in her 20s developed a cutaneous eruption on her left leg 3 days after returning from a trout fishing trip in a freshwater lake. She recalled having a small abrasion on her left leg before wading waist-deep in search of trout. Prior to presentation, she was unsuccessfully treated by 3 different physicians for allergic contact dermatitis and cellulitis. Attempted treatments included topical and oral corticosteroids, trimethoprim-sulfamethoxazole, ceftriaxone, doxycycline, and clindamycin. Following 1 month of failed treatment, she presented to the dermatology clinic. Physical examination revealed erythematous, crusted, edematous plaques and pustules with weeping of yellow exudate on the left leg (Figure, A). Plaques extended from the lower mid-shin to the thigh in a sporotrichoid spread, ending with a palpable enlarged lymph node in the left groin. The left leg was tender to palpation. The patient reported no history of cutaneous eruptions on her legs or feet, and there was no obvious thickening, yellowish discoloration, or subungual debris of the fingernails or toenails on examination. A laboratory work-up, potassium hydroxide scraping (Figure, C), and punch biopsies for histopathologic analysis and fungal, bacterial, and atypical mycobacterial tissue cultures were performed.
Nemer KM, Denny G, Mann CM. Crusted Papules and Pustules on the Leg After a Trout Fishing Trip. JAMA Dermatol. Published online February 15, 2017. doi:10.1001/jamadermatol.2016.6200