Desquamative gingivitis is an oral sign of systemic changes that may be symptomatic or asymptomatic. It is generally related to immunological changes. This report is aimed at describing the case of a 51-year-old female patient, who presented with clinical desquamative gingivitis and was initially diagnosed and treated as necrotizing periodontal disease, but no improvement. The cause was hypothesized to be an autoimmune disease. Drug therapy was initiated as a combination of prednisone and topical clobetasol propionate 0.5% cream twice a day. After this treatment, there was an improvement in pain and the blistering of the gingiva. However, the gingiva remained erythematous. A biopsy led to the diagnosis of benign mucous membrane pemphigoid (BMMP). The BMMP case reported in this article has been successfully treated with systemic and topical immunosuppressive therapy. The efficacy of systemic corticosteroids with dapsone and multidisciplinary follow-up has been highlighted and can lead to the stabilization and adequate control of the disease.