Erythema Ab Igne: Background, Pathophysiology, Etiology

Open fires reportedly result in erythema ab igne. Typically, erythema ab igne affects the legs of women aged 40-70 years who use indoor fire as a heat source. Erythema ab igne reportedly affects the face and/or palms of cooks who work over an open fire.

Some patients use a heat source (eg, heating pad, hot water bottle, heated recliner, heated blanket) to relieve chronic pain.
[5] In these patients, determine the etiology of the pain. In the case of heating pads and/or hot water bottles, erythema ab igne can occur in patients with pain associated with either primary or metastatic malignancy, as well as with pain associated with chronic pancreatitis.
[6, 7, 8] Heated recliners (reclining chairs) have been reported to cause erythema ab igne in patients with chronic lower back pain.
[9] The application of heated popcorn kernels applied to the skin to reduce arthritic pain caused erythema ab igne in one patient.
[10] One case report describes erythema ab igne in a patient with diabetic neuropathy.
[11]

Other heat sources may be involved. Erythema ab igne has been described subsequent to sauna belt usage for abdominal obesity.
[12] A car heater reportedly caused erythema ab igne in one patient.
[13] More recently, using laptop computers while they are propped on the legs has resulted in the development of erythema ab igne. Some laptop computers can generate significant heat that can result in erythema ab igne when placed on the lap for prolonged periods.
[14, 15, 16, 17, 18]

The following is a summary of heat sources reported to cause erythema ab igne
[3, 19, 20] :

• Heating pads

• Hot water bottles

• Electric stoves/heater

• Open fires

• Coal stoves

• Peat fires

• Wood stoves

• Steam radiators

• Car heaters

• Heated reclining chairs

• Heating or electric blanket

• Hot bricks

• Infrared lamps

• Microwave popcorn

• Laptop computer

• Automobile seat heater

• Hot bathing