A comparison of IgA positive and IgA negative dapsone responsive dermatoses

Diagnosis of bullous disease and studies in the pathogenesis of blister formation using immunopathological techniques

Several skin diseases may present as vesicles or bullae. Immunofluorescent studies are very helpful in differentiating the various disease entities. Familiarity with the procedure and the various kinds of patterns that are specific and non-specific is essential for the practicing dermatologist. Immunofluorescent patterns are particularly helpful in differentiating pemphigus, bullous pemphigoid, cicatrical pemphigoid, herpes gestationis, dermatitis herpetiformis, linear IgA dermatosis and porphyria. Immunofluorescent studies of the skin and sera of these patients were vital to an understanding their pathogenesis. Immunoelectron microscopy has further helped in delineating the exact sites of immunoglobulin deposition, and, thus, identifying the location of the antigens. In pemphigus, studies at the molecular level reveal that the basic pathological process is mediated by an anti-cellular cement substance antibody. The binding of this antibody at the cell surface level results in a process that is seen at the light microscopy level in the form of acantholysis. In bullous pemphigoid cells may play an important role. It appears that the mast cell, eosinophil, and the lymphocyte in harmony with the polymorphonuclear leucocyte work together to bring about an enzymatic degradation of the basement membrane. The specific role of the anti-basement membrane zone antibody is also under current study. With advances in molecular immunology, especially monoclonal antibodies and gene technology, it is hoped that these cellular and molecular interactions will be better understood and further defined.

Disodium cromoglycate in dermatitis herpetiformis

Eleven patients with dermatitis herpetiformis, all requiring dapsone to control their rash and taking a normal diet, were given disodium cromoglycate (DSCG) 1.5-1.6 g daily. Eight out of the eleven patients continued to take DSCG for periods varying from 6-11 months, the other three patients chose to discontinue the DSCG before 6 months. Of the eight patients taking DSCG for at least 6 months, none was able to stop taking dapsone. In three of the eight, the dapsone requirements were unaltered, whilst in two it decreased and in three it increased. The mean daily dose of dapsone was 105 mg/day before DSCG and 141 mg/day after DSCG. In the eight patients who took DSCG for at least 6 months, intestinal biopsies were performed before and after this drug. The macroscopic appearance was unchanged in four, improved in two and worse in two. The mean interepithelial lymphocyte count was 346 before and 342 after DSG.