Annular lipoatrophy of the ankles.

Lipoatrophic panniculitis likely represents a group of disorders characterized by an inflammatory panniculitis followed by lipoatrophy. It occurs locally in a variety of settings and has been reported in the literature under various terms, including annular atrophic connective tissue panniculitis of the ankles, annular and semicircular lipoatrophy, abdominal lipoatrophy, and connective tissue panniculitis. Herein, a case of annular lipoatrophy of the ankles is described in a 6-year-old girl with autoimmune thyroid disease. Histologically, a mixed lobular panniculitis with lipophages was present. This pattern resembles that seen in lipoatrophic panniculitis. After a single, acute episode of an inflammatory process with subsequent lipoatrophy, her skin lesions have stabilized for 2 years requiring no treatment.

Identification of a potential effector function for IgE autoantibodies in the organ-specific autoimmune disease bullous pemphigoid.

Bullous pemphigoid (BP) is an autoimmune skin disease characterized by autoantibodies against the hemidesmosomal protein BP180. In addition to IgG autoantibodies, IgE class autoantibodies have been reported in BP patients. Because animal models utilizing only IgG antibodies do not totally replicate human BP, we examined the specificity and potential relevance of IgE autoantibodies in this disease. Thirty BP patients participated in these studies. Serum IgE was measured and the IgE specificity was determined by immunoblotting. Double labeling Immunofluorescence was performed using combinations of specific antibodies to human mast cell tryptase, IgE and BP180. BP180-stimulated histamine release was measured from basophils of untreated BP patients (n=9), BP patients undergoing immunosuppressive therapy (n=9) and controls (n=16). Elevated IgE levels were found In 70% of untreated BP patients. IgE autoantibodies directed against BP180 were detected in 86% of untreated patients and in all but one of these patients the IgE reacted with the NC16A domain of BP180. IgE-coated mast cells were detected in perilesional skin of the BP patients. Moreover, BP180 peptides were detected on these mast cells. BP180-stimulated histamine release was significantly higher in basophils obtained from untreated BP patients compared with control basophils (p=0.006) or from treated BP patients (p=0.01). These findings support the hypothesis that IgE autoantibodies are involved in the pathogenesis of BP. IgE and IgG BP autoantibodies share the same antigenic specificity. Antigen-specific degranulation of basophils and/or mast cells from BP patients suggests a mechanism by which IgE may contribute to lesion development.