Erythema ab igne in Adult
Although burns do not occur from the heat exposure, the skin develops mottled, reticulated (net-like), pink, reddish, or violaceous patches that eventually become brown from melanin deposition. There may be pruritus or mild burning paresthesias. Rarely, vesicles or bullae have been described in affected areas. The resultant pigmentation changes can be permanent. Currently, there is no effective treatment for them. The disorder is more common in women. One retrospective study found an approximately 2:1 female predominance, with the anterior legs being the most common site affected.
Chronic exposure to infrared radiation in the form of heat may predispose to the development of malignancy, with squamous cell carcinoma (SCC), or rarely Merkel cell carcinoma, having been observed in isolated cases of EAI.
L59.0 – Erythema ab igne
238510001 – Erythema ab igne
Differential Diagnosis & Pitfalls
- Differentiate from livedo reticularis and cutis marmorata, which are more erythematous and vascular appearing, have no associated hyperpigmentation, and are not related to heat exposure. They are more likely to be related to cold exposure.
- Livedo racemosa
- Livedoid vasculopathy
- Acanthosis nigricans
- Cholesterol emboli
- Lupus erythematosus
- Polyarteritis nodosa
- Reticular telangiectatic erythema – Skin over an implanted spinal cord stimulator may show changes with erythema and telangiectasia that have been called "reticular telangiectatic erythema." It is often related to localized heating due to a defect in the implanted device.
- Serpentine supravenous hyperpigmentation (see drug-induced pigmentation)