Chapter 055. Immunologically Mediated Skin Diseases (Part 10) pot

Chapter 055. Immunologically Mediated Skin Diseases (Part 10) Scleroderma often eventuates in development of an expressionless, mask- like facies. Morphea is characterized by localized thickening and sclerosis of skin, usually affecting young adults or children. Morphea begins as erythematous or flesh-colored plaques that become sclerotic, develop central hypopigmentation, and demonstrate an erythematous border. In most cases, patients have one or a few lesions, and the disease is termed localized morphea. In some patients, widespread cutaneous lesions may occur, without systemic involvement. This form is called generalized morphea. Most patients with morphea do not have autoantibodies. Skin biopsy of morphea is indistinguishable from that of scleroderma. Linear scleroderma is a limited form of disease that presents in a linear, bandlike distribution and tends to involve deep as well as superficial layers of skin. Scleroderma and morphea are usually quite resistant to therapy. For this reason, physical therapy to prevent joint contractures and to maintain function is employed and is often helpful. Diffuse fasciitis with eosinophilia is a clinical entity that can sometimes be confused with scleroderma. There is usually the sudden onset of swelling, induration, and erythema of the extremities frequently following significant physical exertion. The proximal portions of extremities (arms, forearms, thighs, legs) are more often involved than are the hands and feet. While the skin is indurated, it is usually not bound down as in scleroderma; contractures may occur early secondary to fascial involvement. The latter may also cause muscle groups to be separated and veins to appear depressed. These skin findings are accompanied by peripheral blood eosinophilia, increased erythrocyte sedimentation rate, and sometimes hypergammaglobulinemia. Deep biopsy of affected areas of skin reveals inflammation and thickening of the deep fascia overlying muscle. An inflammatory infiltrate composed of eosinophils and mononuclear cells is usually found. Patients with eosinophilic fasciitis appear to be at increased risk to develop bone marrow failure or other hematologic abnormalities. While the ultimate course of eosinophilic fasciitis is uncertain, many patients respond favorably to treatment with prednisone in doses ranging from 40–60 mg/d. The eosinophilia-myalgia syndrome, a disorder reported in epidemic numbers in 1989 and linked to ingestion of L-tryptophan manufactured by a single company in Japan, is a multisystem disorder characterized by debilitating myalgias and absolute eosinophilia in association with varying combinations of arthralgias, pulmonary symptoms, and peripheral edema. In a later phase (i.e., 3–6 months after initial symptoms), these patients often develop localized sclerodermatous skin changes, weight loss, and/or neuropathy (Chap. 316). The precise cause of this syndrome, which may resemble other sclerotic skin conditions, is unknown. However, the implicated lots of L-tryptophan contained the contaminant 1,1-ethylidene bis[tryptophan]. This contaminant may be pathogenic or a marker for another substance that provokes the disorder. Further Readings Anhalt GJ: Paraneoplastic pemphigus. J Investig Dermatol Symp Proc 9:29, 2004 [PMID: 14870982] Braverman IM: Connective tissue diseases, in Skin Signs of Systemic Disease, 3d ed. Philadelphia, Saunders, 1998 Mutasim DF et al: Immunobullous diseases. J Am Acad Dermatol 52:1029, 2005 [PMID: 15928622] Payne AS et al: Desmosomes and disease: Pemphigus and bullous impetigo. Curr Opin Cell Biol 16:536, 2004 [PMID: 15363804] Schmidt E, Zillikens D: Autoimmune and inherited subepidermal blistering diseases: Advances in the clinic and the laboratory. Adv Dermatol 16:113, 2000 [PMID: 11094626] Sontheimer RD: Skin manifestatio ns of systemic autoimmune connective tissue disease: Diagnostics and therapeutics. Best Pract Res Clin Rheumatol 18:429, 2004 [PMID: 15158749] Udey MC, Stanley JR: Pemphigus— diseases of antidesmosomal autoimmunity. JAMA 282:572, 1999 [PMID: 10450720] Y ancey KB, Egan CA: Pemphigoid: Clinical, histologic, immunopathologic, and therapeutic considerations. JAMA 284:350, 2000 [PMID: 10891967] . Chapter 055. Immunologically Mediated Skin Diseases (Part 10) Scleroderma often eventuates in development of an expressionless,. 14870982] Braverman IM: Connective tissue diseases, in Skin Signs of Systemic Disease, 3d ed. Philadelphia, Saunders, 1998 Mutasim DF et al: Immunobullous diseases. J Am Acad Dermatol 52:1029,. develop localized sclerodermatous skin changes, weight loss, and/or neuropathy (Chap. 316). The precise cause of this syndrome, which may resemble other sclerotic skin conditions, is unknown. However,