Abstract

Discoid lupus erythematosus (DLE), a chronic variant of cutaneous lupus erythematosus (CLE), typically presents as well-defined and scaly erythematous plaques that most commonly involve the head, neck, and upper trunk. In later stages of disease, DLE can lead to atrophic scars and dyspigmentation. Herein, we present a case of inverse, intertriginous, and acral involvement of DLE in a 67-year-old woman with a two year history of indurated, annular scaly plaques with central hypopigmentation. She had a long history of seronegative rheumatoid arthritis treated with methotrexate and etanercept, and concomitant Sjogren’s syndrome. Laboratory testing demonstrated positive anti-nuclear antibody (titer 1:640) with SSA+ antibodies, consistent with her known Sjogren’s. Urinalysis was negative. On histopathologic evaluation, there was an interface dermatitis with superficial and deep perivascular and periadnexal lymphocytic infiltrates and basement membrane thickening. Alcian blue staining demonstrated increased dermal mucin. She had no other signs or symptoms of systemic lupus erythematosus. Further, drug-induced causes of CLE, specifically from her long-term TNF inhibitor use, is thought to be less likely based on her clinical presentation and time course. Clinico-pathologic correlation supported a diagnosis of inverse and acral DLE. While acral involvement is a well-documented presentation of DLE based on literature review, our patient’s inverse cutaneous distribution is unique and striking.

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