Lupus Erythematosus Tumidus as a Distinct Uncommon Subtype of Cutaneous Lupus Erythematosus: A Case Report and Review.

Lupus erythematosus tumidus (LET) is an uncommon but distinct photosensitive subtype of cutaneous lupus erythematosus (CLE). It differs from discoid and subacute cutaneous lupus erythematosus (SCLE) clinically and pathologically. LET is marked by extreme photosensitivity and carries a much lower risk of progression to systemic disease. The differential diagnosis of LET includes polymorphic light eruption (PMLE) and Jessner's lymphocytic infiltration of the skin (JLIS) because of subtle alterations in the histopathology and the paucity of immunopathologic markers in LET. We report herein a case of LET with positive immunoglobulin (Ig) deposits on direct immunofluorescence (DIF) testing. LET resolved completely with strict sun avoidance and treatment with topical corticosteroids, without the sequelae of atrophy, scarring, or dyspigmentation.