 Any mucous membrane can be involved, but the most commonly involved site is the oral mucosa, followed by conjunctiva, skin, pharynx, external genitalia, nasal mucosa, larynx, anus, and esophagus.As MMP may lead to serious complications such as blindness and airway compression, early and aggressive treatment initiation may be needed.Scarring is a common consequence of MMP that distinguishes this variant from mucosal involvement in bullous pemphigoid, which typically does not scar.