In the bullous stage, BP can be misdiagnosed as other subepidermal blistering dermatoses like linear IgA bullous dermatosis (LABD), dermatitis herpetiformis, EBA, MMP, anti p-200/laminin γ1 pemphigoid, bullous lupus erythematous, and fixed drug eruption. Here, OCA2 is linked to autoimmune bullous skin disease.