B

Erosive (ulcerative) oral lichen planus typically involves the gingiva, producing erythematous, ulcerated and sloughing tissue that is clinically described as desquamative gingivitis, the same appearance seen in mucous membrane pemphigoid and pemphigus [Vatankhah et al., 2010, PMID 22991593; Vaillant et al., 2000, PMID 10844258].