Painful nodule on the foot of a traveller returning from Africa

Abstract

A 64-year-old man presented to the emergency department with a 3-week history of a single painful bleeding lesion on his left heel. The patient had been on a recent holiday to Mozambique, and the lesion appeared after his return.On physical examination, a single hyperkeratotic yellow nodule with a black punctum was seen on the patient's heel (Fig. 1a). Dermoscopic examination was undertaken (Fig. 1b). The lesion was punch excised under local anaesthetic in clinic, and the tissue was sent for histological evaluation. Histopathological findingsOn histological examination, a cavity in the stratum corneum was seen, lined by a thick eosinophilic cuticle with spike-like projections (Fig. 2). Inside the cavity, there were multiple ring-like structures, as well as round and oval-shaped structures containing granules (Figs 3a,b).What is your diagnosis? (a) (b) Figure 1 (a) Painful hyperkeratotic nodule on the left heel; (b) dermatoscopic view of the hyperkeratotic nodule, showing punctum.