A pruritic vesicular rash

A man, 30 years of age, presented with an intensely pruritic eruption that had been evolving for approximately two months. The rash was characterised by clusters of translucent, tense vesicles located symmetrically on the extensor surfaces of the arms and legs (Figure 1A, B), and by erythematous papules and small plaques on the buttocks (Figure 1C). Some of the lesions were excoriated with bloodstained crusting. The patient reported a loss of approximately 5 kg in weight, and several episodes of diarrhoea and abdominal discomfort in the previous year. The patient was otherwise healthy and denied any history of fever, photosensitivity or symptoms in other family members. Four punch biopsies of lesional and perilesional skin from the arms and buttocks were taken for routine histopathology and direct immunofluorescence (DIF).