A Case of Thermal Keratosis along with Erythema Ab Igne

Hwang, Chul; Back, Seung Ju; Choi, Dae Kyoung; Seo, Young June; Park, Jang Kyu; Lee, Jeung Hoon

Abstract

We report a case of thermal keratosis with erythema ab igne which occurred on the dorsal side of a patient's left hand due to chronic exposure to infrared rays. A 62-year-old male presented with reticular hyperpigmentation on the dorsal side of his left hand and left knee along with multiple hyperkeratotic nodules on the dorsal side of his left hand without any symptoms. He had a hobby of playing internet games with a heater on his left side. A skin biopsy of the hyperkeratotic lesion showed hyperkeratosis and acanthosis in the epidermis. The dermis revealed many elastic fibers and superficial perivascular monocytic infiltration. The patient was diagnosed with thermal keratosis and erythema ab igne due to his history of chronic infrared exposure, distinctive clinical characteristics and the biopsy results. The application of topical steroid with the recommendation to cease exposure to heaters resulted in the almost disappearance of the papules and a little restoration of the skin color.