A man presents with pruritic, serpiginous cords on his left foot. What are these lesions and how should they be treated?
After a beach holiday in Thailand, a 23-year-old man developed pruritic, serpiginous cords on the sole and medial aspect of his left foot (Figure 1). The cords had commenced with an itchy papule, which over the following three weeks formed an erratic intersecting pattern with focal areas that were eroded, crusted, pustular or haemorrhagic. A skin biopsy showed subepidermal and intraepidermal blisters with eosinophils that extended diffusely into the underlying dermis and subcutis (Figure 2). No organisms were seen.