A malignant rash

Doctors are being urged to keep an eye out for Merkel cell carcinoma after a woman was mistakenly diagnosed with allergic contact dermatitis.

The 91-year-old presented to the ED with a five-day history of erythematous rash and was told she had allergic contact dermatitis.

However, histological examination of a 1.5cm excised nodule revealed she had Merkel cell carcinoma — a rare and aggressive type of skin cancer.

According to the case report authors, diagnosis of Merkel cell carcinoma is often delayed, which contributes to the high