Erythema Ab Igne

This article is an answer to the Case – Reticular Hyperpigmentation

A skin biopsy showed a perivascular lymphocytic infiltrate with hemosiderin deposition in the upper dermis. A diagnosis of erythema ab igne was made.

Erythema ab igne is a dermatosis that results from long-term heat exposure. It manifests as an erythematous or hyperpigmented reticulation that can occur anywhere on the body and can be distributed asymmetrically, depending on the location of the external heat source. It may be confused with vasculitis.

The patient was advised to avoid further direct heat exposure. At a 3-week follow-up visit, the hyperpigmentation had decreased, but the hypopigmented scars,which may have been from mild burns, persisted.

SIMILAR CASE: Mottled Darkening of the Skin on the Left Thigh


  • Atanu Chandra, Abheek Sil, Souvik Das, Uddalak Chakraborty. (2023) Erythema ab igne: a cutaneous marker of prolonged thermal exposure. BMJ Case Reports 16:8, e256612.
  • Joshua Haron Abasszade, Timothy Abrahams, Chih Chien Kuan, Lik Hui Lau. (2023) Erythema Ab igne. BMJ Case Reports 16:5, e255308.