Erythema Ab Igne with Histological Features of Keratosis Lichenoides Chronica

Erythema ab igne (EAI) is a localized, hyperpigmented and reticulated dermatosis at sites of chronic heat exposure. Within longstanding skin lesions of EAI, hyperkeratotic lesions may emerge and can potentially transform into pre-malignant or malignant skin lesions. A 55-year-old woman presented for the evaluation of multiple hyperkeratotic lesions along with a reticular patterned hyperpigmentation on her right knee, an area that had repeated and prolonged exposure to a heat source over a period of several months. Based on her clinical history and the physical examination of her lesions, she was diagnosed as having a hyperkeratotic form of EAI. A skin biopsy was performed to rule out malignant alteration, but the histopathological findings were supportive of keratosis lichenoides chronica.

Erythema ab igne masking cutaneous metastasis of colorectal adenocarcinoma

Skin metastasis commonly manifest as subcutaneous or intradermal violaceous nodules that coalesce with a firm rubbery appearance. Few cases reported an erythema ab igne-like appearance in the presence of internal malignancy. We report a case of metastatic colorectal adenocarcinoma with erythema ab igne-like presentation. We also review cases of erythema ab igne in association with internal malignancy.