Inverse Gottron's papules: an unusual cutaneous manifestation of juvenile dermatomyositis.

Dermatomyositis is an autoimmune inflammatory myopathy characterized by unique cutaneous features. Gottron's papules are pathognomonic, lichenoid papules that can be found overlying the joints of the dorsal hand. Papules on the palms of the hand are less commonly seen, especially in the pediatric age group. Recognition of these inverse Gottron's papules as a sign of dermatomyositis is important as they may be the only cutaneous feature and may be a clue of underlying interstitial lung disease.

Clear cell papulosis in Hispanic siblings.

BACKGROUND: Clear cell papulosis is a rare condition that has been reported in 14 children, all but 1 of whom are of Asian descent. It was first described in 1987 and is thus named because of the presence of clear cells in the epidermis. OBSERVATION: We describe the cases of 3 Hispanic children in the United States with clear cell papulosis. All 3 patients presented with multiple grouped, oval, hypopigmented macules and flat papules in the suprapubic area and trunk. Histopathologic examination revealed characteristic clear cells within the basal layer and Malpighian layer. CONCLUSIONS: Clear cell papulosis is a unique entity with most cases reported in patients of Asian heritage. The characteristic cells have histologic and immunohistochemical similarities to Paget cells and Toker clear cells of the nipple, although the exact relationship to these cells is not clear. The natural history of clear cell papulosis is unknown; thus, continual surveillance for development of extramammary Paget disease is suggested.

Linear IgA dermatosis with IgA and IgG autoantibodies to the 180 kDa bullous pemphigoid antigen (BP180): evidence for a distinct subtype.

BACKGROUND: Autoantibodies in linear immunoglobulin A (IgA) disease (LAD) are reported to be of IgA class and directed against a 97-120 kDa epidermal antigen. METHODS: We report a 39-year-old woman with clinical features of LAD and with circulating IgA and IgG autoantibodies to the 180 kDa bullous pemphigoid antigen (BP180). RESULTS: Histopathology of lesional skin revealed a subepidermal blister with mixed inflammatory cell infiltrate. Direct immunofluorescence of perilesional skin showed linear deposits of IgA along the dermal-epidermal junction. The antigen specificity of the patient's circulating antibodies was determined by Western blotting and enzyme-linked immunoabsorbent assay (ELISA) using various antigen sources, including cultured human keratinocytes, dermal protein lysates, and purified laminin-5, as well as proteins corresponding to BP180, the 230 kDa bullous pemphigoid antigen (BP230), laminin-5 subunits, and collagen IV alpha1-alpha6 chains. IgA and IgG antibodies in the patient's serum were directed against BP180, and no IgA or IgG reactivity was found against the other skin antigens. CONCLUSIONS: These data provide evidence for the presence of a subtype of LAD with dual IgA and IgG autoimmune response to BP180.