133 - Lichen myxedematosus

Abstract

Lichen myxedematosus (LM) is a rare, chronic, papular mucinosis characterized by infiltration of the skin with mucin-producing fibroblasts. Typical examination findings include shiny, skin-colored to erythematous papules, nodules, and plaques on the face and/or extremities. There are three major subtypes, including localized LM; scleromyxedema, which is more generalized; and atypical/intermediate, which has overlapping features. On histopathology, mucin deposition is typically present and fibroblast proliferation is also seen, but the degree depends on the subtype. The systemic form, scleromyxedema, is most notably associated with monoclonal IgG lambda gammopathy, esophageal dysmotility, myopathy, and dermatoneuro syndrome. Other, more recently discovered associations include hepatitis C, HIV, and hypergammaglobulinemia. The localized form lacks these systemic associations and presents as acral persistent papular mucinosis, self-healing papular mucinosis, discrete LM, nodular LM, or cutaneous mucinosis of infancy. The differential diagnosis includes other skin-colored, white, papular or nodular eruptions such as molluscum contagiosum, granuloma annulare, and lichen planus. The diagnosis is often established using a skin biopsy. Treatment is dependent on the extent and presence of systemic changes. The systemic form, scleromyxedema, is typically treated with intravenous immunoglobulin alone or with adjunctive therapies. For localized forms of LM, immunomodulatory or destructive therapies such as corticosteroids, calcineurin inhibitors, cryotherapy, carbon dioxide laser, dermabrasion, or hyaluronidase are used. Treatment-resistant forms of the disease often require multiple modalities.