Erythema Ab Igne from Heating Pad Use: A Report of Three Clinical Cases and a Differential Diagnosis

Abstract

Erythema ab igne is an asymptomatic cutaneous disorder characterized by erythematous reticulated hyperpigmentation resulting from chronic exposure to infrared radiation in the form of heat. We report three cases of erythema ab igne from chronic heating pad use over a duration of six months to three years. The lesions were asymptomatic in all three patients and were incidental skin findings in two patients, unrelated to their chief complaints. This illustrates the importance of recognizing the morphology and distribution of erythema ab igne. Additionally, knowledge of similarly presenting cutaneous diseases is important to distinguish erythema ab igne from other more worrisome entities that would require further evaluation. Our patients were informed of the benign nature of this condition and were told that cessation of heating pad use would likely result in the resolution of their lesions.

Keywords: erythema ab igne; heating pad.

Figure 1. Patient 1. Erythema ab igne

Erythematous reticulated hyperpigmentation on the back.

Figure 2. Patient 2: Erythema ab igne

Reddish-brown reticulated patches on the lower abdomen.

Figure 3. Patient 3: Erythema ab igne

Reticulated hyperpigmented patches on the lower back.