Erythema ab Igne in a 50-Year-Old Obese Woman

The husband of this 50-year-old obese woman noted that her back was discolored. Review of past medical history disclosed long-standing low back pain from partially herniated vertebral disks.

Key point: The distinct appearance of this lacy, reticulated red-brown macular eruption is characteristic for erythema ab igne. This disorder is the cutaneous response to prolonged and repeated application of heat to the same skin surface. The patient admitted to sitting and sleeping on a heating pad placed on the affected potion of the back.

Treatment: There is no specific therapy, except to recommend discontinuation of continuing exposure to heat.

Note: There are cases of erythema ab igne that have ultimately developed either in-situ or invasive squamous cell carcinoma within the discolored zone. When this risk is explained to the patient, the underlying behavior is frequently curtailed.