RT Book, Section A1 Hashimoto, Takashi A2 Kang, Sewon A2 Amagai, Masayuki A2 Bruckner, Anna L. A2 Enk, Alexander H. A2 Margolis, David J. A2 McMichael, Amy J. A2 Orringer, Jeffrey S. SR Print(0) ID 1161331806 T1 Intercellular Immunoglobulin (Ig) A Dermatosis (IgA Pemphigus) T2 Fitzpatrick's Dermatology, 9e YR 2019 FD 2019 PB McGraw-Hill Education PP New York, NY SN 9780071837798 LK dermatology.mhmedical.com/content.aspx?aid=1161331806 RD 2024/03/28 AB AT-A-GLANCEIntercellular immunoglobulin (Ig) A dermatosis (IAD) is a chronic vesicular and/or pustular autoimmune skin disease caused by IgA, not by IgG, antibodies.Two major types: subcorneal pustular dermatosis (SPD)-type IAD and intraepidermal neutrophilic IgA dermatosis (IEN)-type IAD.SPD-type IAD clinically shows superficial pustules on the intertriginous areas.IEN-type IAD clinically shows atypical pustular skin lesions with a sunflower-like configuration.Diagnosis is made by histopathology showing intraepidermal pustules, immunofluorescence detecting in vivo bound and/or circulating IgA antikeratinocyte cell-surface autoantibodies, and various biochemical and molecular biologic methods demonstrating reactivity with various autoantigens.SPD-type IAD shows histopathologically subcorneal neutrophilic pustules.IEN-type IAD shows histopathologically neutrophilic pustules in the middle epidermis.Major autoantigens are desmogleins (Dsg) and desmocollins (Dsc), cadherin-type cell-to-cell adhesion molecules found in desmosomes.Patients are treated mainly with dapsone and systemic corticosteroids; other treatment options include immunosuppressive agents, tetracycline, colchicine, plasmapheresis, retinoids, adalimumab, and psoralen and ultraviolet A.