Erythema ab igne is a localized area of erythema and hyperpigmentation in a reticular pattern due to repeated exposure to heat. It is because of injury to the epidermis and superficial vascular plexus. Found mainly in the middle age adults, usually overweight women. Erythema ab igne is classically seen on the inner thighs and legs of women who sit near the open fire, stove, or an electric heater. It can occur due to heating pads, hot water bottles, infrared lamps, and even laptop computers. Occasionally, it can be a sign of underlying disease when patients apply external heat to relieve the pain, like backache, splenomegaly, pancreatitis, pancreatic and other malignancies. The prognosis is good, except for cases associated with internal disease. Early changes, such as erythema and mild hyperpigmentation may resolve in months, but chronic exposure may result in permanent changes. Thermal keratosis, squamous cell carcinoma in situ, and squamous cell carcinoma have been reported in the lesions of erythema ab igne.
Habibullah Khan. (2016) ERYTHEMA AB IGNE, Gomal Journal of Medical Sciences , Volume 14, Issue 4.