Chapter 13 - Discoid Lupus Erythematosus

Abstract

Discoid lupus erythematosus (DLE), a type of chronic cutaneous lupus erythematosus, is an important cause of scarring alopecia. The incidence of DLE is higher among women than men, and it tends to occur most commonly in the fifth decade of life. It is an autoimmune condition triggered by environmental stressors in individuals with an unknown underlying genetic predisposition. Environmental stressors implicated in this condition include ultraviolet irradiation, hormones, medications, infections, and cigarette smoking. The characteristic erythematous, scaly plaques frequently appear first on the scalp and may be misdiagnosed as alopecia areata, lichen planopilaris, or pseudopelade of Brocq. Scalp trichoscopy can be helpful to identify the characteristic features of scalp DLE: loss of follicular orifices, follicular keratotic plugs, large yellow dots, and thick arborizing vessels. Biopsy of scalp lesions is important to differentiate among various causes of inflammatory alopecia, and direct immunofluorescence can be helpful to confirm the diagnosis. Treatment involves removal of environmental triggers and a tiered therapeutic approach. First-line therapies include high-potency topical steroids and topical calcineurin inhibitors. Patients who fail topical treatments can be treated with an antimalarial medication as first-line systemic treatment. Some evidence supports the use of oral retinoids or methotrexate for refractory cases. There are no biologic agents approved for the treatment of DLE, but case reports indicate that antiinterferon-α monoclonal antibodies may be effective. Identification of alopecia caused by DLE is important because untreated lesions may rarely progress to malignancy.