IgG and C3 deposits are found along the basement membrane. Occasionally, linear deposition of IgA at the basement membrane zone can also be seen. Multiple and repeated biopsies increase the sensitivity of DIF studies to diagnose MMP. Indirect immunofluorescence Indirect immunofluorescence is used to detect circulating antibodies targeting the antigens at the basement membrane zone in patients with pemphigoid. In early studies using routine techniques, only one third of patient with MPP were being tested positive. Circulating IgG and IgA antibodies are found in patient's serum. To increase the likelihood of detecting circulating antibodies, human basement membrane zone-split skin and/or concentrated serum should be used. Antigen-specific serologic testing Autoantibodies directed against a variety of antigens, including BP180, BP230, laminin 332, and type VII collagen may be detected. However, this test could not be used as the only diagnostic tool for testing as ELISA testing has limited sensitivity. Treatment The factors that determine the type of therapy used for mucous membrane pemphigoid are: [1] site(s) of involvement, [2] severity of disease, [3] rate of progression. Oral mucosa is the most common site being affected in mucous membrane pemphigoid. For the mild oral mucosa lesion, high potency topical steroids such as 0.05% Clobetasol propionate is used. Patients are instructed to apply the ointment or gel 2-3 times a day after drying the oral mucosa to enhance the adherence of mediation to oral mucosa. Patients are instructed to avoid drinking or eating for at least 30 minutes after application. Dental tray can also be fabricated to help in the application of topical steroids to lesional sites under occlusion for patients with gingival involvement. Furthermore, topical tacrolimus, a calcineurin inhibitor, has also shown to be effective to control the disease, including some patients who failed to respond well to topical corticosteroids. Topical tacrolimus 0.1% ointment is applied two to three times a day and tapered after improvement in healing of pemphigoid. Another method is to use intralesional corticosteroids (Triamcinolone acetonide, dilution of 5 to 10 mg/ml; repeated every 2–4 weeks). Intralesional therapy is used when the patient does not respond to local therapies. For moderate to severe disease (including the ones involving ocular, nasopharyngeal, or anogenital mucosa) and patient who did not respond to local therapy adequately, systemic agents should be used. Systemic corticosteroids and dapsone are used in such cases. The dose of dapsone ranges from 50 to 200 mg daily. Dapsone is