ESSENTIALS OF DIAGNOSIS
Localized violaceous red plaques, usually on the head (discoid lupus erythematosus) or the trunk (chronic cutaneous lupus erythematosus).
Scaling, follicular plugging, atrophy, dyspigmentation, and telangiectasia of involved areas.
Common forms of cutaneous lupus include chronic cutaneous lupus erythematosus (CCLE), typically chronic scarring (discoid) lupus erythematosus (DLE), and erythematous nonscarring red plaques of subacute cutaneous lupus erythematosus (SCLE). All occur most frequently in photoexposed areas (eFigure 6–82). Permanent hair loss and loss of pigmentation are common sequelae of discoid lesions. SLE is discussed in Chapter 20. Patients with SLE may have DLE or SCLE lesions.
Malar and facial erythema and scale in a 22-year-old woman with a flare of acute cutaneous lupus. This patient has had SLE since age 17 and the flare occurred after extended sun exposure. Note how the flare is not just on the malar area. (Reproduced with permission from Richard P. Usatine, MD, in Usatine RP, Smith MA, Mayeaux EJ Jr, Chumley HS. The Color Atlas and Synopsis of Family Medicine, 3rd ed. McGraw-Hill, 2019.)
Symptoms are usually mild. In DLE, the lesions consist of violaceous red, well-localized, single or multiple plaques, 5–20 mm in diameter, usually on the face, scalp, and external ears (conchal bowl) (eFigure 6–83)(eFigure 6–84). In discoid lesions, there is atrophy, telangiectasia, central depigmentation or scarring, a hyperpigmented rim, and follicular plugging. On the scalp, significant permanent hair loss may occur. In SCLE, the lesions are erythematous annular or psoriasiform plaques up to several centimeters in diameter and favor the upper chest and back (eFigure 6–85).
Discoid lupus erythematosus of the arm. (Used, with permission, from Lindy Fox, MD).
Discoid lupus of the face and ear in a darkly pigmented patient. (Used with permission, from Lindy Fox, MD.)
Subacute cutaneous lupus erythematosus: erythematous nonscarring red plaques on the back. (Used, with permission, from Lindy Fox, MD).
In patients with DLE, SLE should be considered if the following findings are present: positive antinuclear antibody (ANA), other positive serologic studies (eg, anti-double-stranded DNA or anti-Smith antibody), high ESR, proteinuria, hypocomplementemia, widespread lesions (not localized to the head), nail fold changes (dilated or thrombosed nail fold capillary loops), or arthralgias with or without arthritis. Patients with marked photosensitivity and symptoms otherwise suggestive of lupus may have negative ANA tests but ...