A relatively rare systemic disease, benign mucous membrane pemphigoid (cicatricial pemphigoid) usually starts in the mouth and is clinically characterized by bullae that rupture and form an ulcer. A distinctive Nikolsky's sign is apparent using gentle air blasts or finger pressure. The pharynx, larynx, nose, esophagus, genitals and eyes can also be affected. Involvement of the conjunctivae can lead to scarring and ensuing blindness. The following case of a healthy 77-year-old man, diagnosed as suffering from mucous membrane pemphigoid, is of particular interest since several confusing clinical observations, including poor oral hygiene, the possibility of a contact dermatitis or an adverse antibiotic reaction, made the diagnosis more difficult. A careful medical history, examination and consultation process is paramount to initiating proper treatment and subsequent relief of symptoms. Benign mucous membrane pemphigoid must always be considered in any patient with desquamative epithelium of the oral mucosa.