Chapter 055. Immunologically Mediated Skin Diseases (Part 8)

Lupus Erythematosus The cutaneous manifestations of lupus erythematosus (LE) (Chap. 313) can be divided into acute, subacute, and chronic types. Acute cutaneous LE is characterized by erythema of the nose and malar eminences in a "butterfly" distribution (Fig. 55-5). The erythema is often sudden in onset, accompanied by edema and fine scale, and correlated with systemic involvement. Patients may have widespread involvement of the face as well as erythema and scaling of the extensor surfaces of the extremities and upper chest. These acute lesions, while sometimes evanescent, usually last for days and are often associated with exacerbations of systemic...
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Chapter 055. Immunologically Mediated Skin Diseases (Part 8) Chapter 055. Immunologically Mediated Skin Diseases (Part 8) Lupus Erythematosus The cutaneous manifestations of lupus erythematosus (LE) (Chap. 313) canbe divided into acute, subacute, and chronic types. Acute cutaneous LE ischaracterized by erythema of the nose and malar eminences in a butterflydistribution (Fig. 55-5). The erythema is often sudden in onset, accompanied byedema and fine scale, and correlated with systemic involvement. Patients mayhave widespread involvement of the face as well as erythema and scaling of theextensor surfaces of the extremities and upper chest. These acute lesions, whilesometimes evanescent, usually last for days and are often associated withexacerbations of systemic disease. Skin biopsy of acute lesions may show only asparse dermal infiltrate of mononuclear cells and dermal edema. In someinstances, cellular infiltrates around blood vessels and hair follicles are notable, asis hydropic degeneration of basal cells of the epidermis. Directimmunofluorescence microscopy of lesional skin frequently reveals deposits ofimmunoglobulin(s) and complement in the epidermal basement membrane zone.Treatment is aimed at control of systemic disease; photoprotection in this, as wellas in other forms of LE, is very important. Figure 55-5 A. Acute cutaneous lupus erythematosus showing prominent, scaly,malar erythema. Involvement of other sun-exposed sites is also common. B. Acutecutaneous LE on the upper chest demonstrating brightly erythematous andslightly edematous papules and plaques. (B, Courtesy of Robert Swerlick, MD.) Subacute cutaneous lupus erythematosus (SCLE) is characterized by awidespread photosensitive, nonscarring eruption. Most of these patients have SLEin which renal and central nervous system involvement is mild or absent. SCLEmay present as a papulosquamous eruption that resembles psoriasis or annularlesions that resemble those seen in erythema multiforme. In the papulosquamousform, discrete erythematous papules arise on the back, chest, shoulders, extensorsurfaces of the arms, and the dorsum of the hands; lesions are uncommon on theface, flexor surfaces of the arms, and below the waist. These slightly scalingpapules tend to merge into large plaques, some with a reticulate appearance. Theannular form involves the same areas and presents with erythematous papules thatevolve into oval, circular, or polycyclic lesions. The lesions of SCLE are morewidespread but have less tendency for scarring than do lesions of discoid LE. Skinbiopsy reveals a dense mononuclear cell infiltrate around hair follicles and bloodvessels in the superficial dermis, combined with hydropic degeneration of basalcells in the epidermis. Direct immunofluorescence microscopy of lesional skinreveals deposits of immunoglobulin(s) in the epidermal basement membrane zonein about half these cases. A particulate pattern of IgG deposition throughout theepidermis has recently been associated with SCLE. Most SCLE patients have anti-Ro autoantibodies. Local therapy alone is usually unsuccessful. Most patientsrequire treatment with aminoquinoline antimalarials. Low-dose therapy with oralglucocorticoids is sometimes necessary. Photoprotective measures against bothultraviolet B and A wavelengths are very important. Discoid lupus erythematosus (DLE, also called chronic cutaneous LE) ischaracterized by discrete lesions, most often found on the face, scalp, and/orexternal ears. The lesions are erythematous papules or plaques with a thick,adherent scale that occludes hair follicles (follicular plugging). When the scale isremoved, its underside shows small excrescences that correlate with the openingsof hair follicles (so called carpet tacking), a finding relatively specific for DLE.Long-standing lesions develop central atrophy, scarring, and hypopigmentationbut frequently have erythematous, sometimes raised borders (Fig. 55-6). Theselesions persist for years and tend to expand slowly. Only 5–10% of patients withDLE meet the American Rheumatism Association criteria for SLE. However,typical discoid lesions are frequently seen in patients with SLE. Biopsy of DLElesions shows hyperkeratosis, follicular plugging, atrophy of the epidermis,hydropic degeneration of basal keratinocytes, and a mononuclear cell infiltrateadjacent to epidermal, adnexal, and microvascular basement membranes. Directimmunofluorescence microscopy demonstrates immunoglobulin(s) andcomplement deposits at the basement membrane zone in ~90% of cases.Treatment is focused on control of local cutaneous disease and consists mainly ofphotoprotection and topical or intralesional glucocorticoids. If local thera ...