Erythema ab igne

**Definition:** A characteristic reticular telangiectatic and pigmented dermatosis resulting from repeated or prolonged exposure to infrared radiation (heat) of insufficient energy to produce a burn. It most commonly affects the lower extremities or lower back as a result of habitually sitting too close to a heat source (radiator or open hearth) or from keeping a hot water bottle held against the skin.

**Exclusions:** - Burns of external body surface, specified by site