In which condition does the oral mucosa appear stiff, pale, and opaque?

Explanation

Submucous fibrosis is characterized by a rigid, blanching, and opaque oral mucosa due to progressive fibrosis of the submucosal tissues. This contrasts with other conditions like pemphigus vulgaris, lupus erythematosus, and Ehlers-Danlos syndrome, which do not typically cause such mucosal changes.