A woman develops a localised, itchy, scaling patch on the back of her hand. What is the cause and how can it be treated?
Over a four-month period, a 42-year-old woman developed a localised itchy patch over the dorsum of her left hand (Figure 1). The erythematous and scaling area had a peripheral desquamating edge, and there were several pustules visible on the fingers. Moisturisers and topical corticosteroids had resulted in only a temporary decrease in the scaling and erythema.