Tender erythematous plaques with fever

A man in his 50s was referred to a community hospital with a 15 day history of fever (38.5°C) and a one week history of painful cutaneous eruptions on his forearms and the crown of the scalp. Before this he had a three month history of abdominal pain and diarrhoea, and a one month history of 3 kg weight loss, but did not seek medical care at that time.

The patient underwent blood tests, the results of which showed neutrophilia and raised C reactive protein. The patient was started on an empirical oral cephalosporin for one week, but showed no improvement.

On presentation to our clinic, physical examination identified tender oedematous erythematous plaques with a pseudovesicular appearance on the head and dorsal aspect of his forearms and hands (fig 1). Repeat laboratory investigations showed an increased …