Squamous cell carcinoma arising in erythema ab igne

Erythema ab igne (EAI) is a red-brown netlike hyperpigmentation due to repetitive exposure to submaximal heat over a long period of time. This rash is typically seen on the anterior lower legs of people who sit in front of open fireplaces or coal stoves and on the trunk of patients with chronic disorders who seek pain relief by long-term use of hot-water bottles or heating pads. EAI can not only be a diagnostic sign for underlying internal diseases including malignant tumors but can also give rise to cutaneous malignancies. We report on a 75-year-old female patient who developed several thermal keratoses and squamous cell carcinomas at the site of erythema ab igne caused by chronic heat exposure over several years.