Each of the following is associated with betel nut chewing EXCEPT:

Mucous membrane pemphigoid is an autoimmune disease NOT associated with betel nut. Betel nut (areca nut) is associated with: oral submucous fibrosis (most characteristic), squamous cell carcinoma, discoloration (red/brown staining), periodontitis, and oral potentially malignant disorders. MMP has autoimmune etiology, not carcinogen-mediated.