A patient presents with red erosive gingival lesions with subepithelial separation on biopsy and symblepharon (adhesion between conjunctiva and eyelid). The MOST likely diagnosis is:

Correct answer: D. Mucous membrane pemphigoid (MMP/cicatricial pemphigoid)

• A. Linear IgA dermatosis is a rare blistering disease — symblepharon is a specific pointer to MMP.
• B. EM causes targetoid lesions and is usually self-limited — not associated with symblepharon.
• C. PV causes suprabasilar (not subepithelial) blistering and does not typically cause ocular symblepharon.
• D. Correct. MMP (mucous membrane pemphigoid) causes subepithelial blistering (hemidesmosomes) and, critically, causes SCARRING of mucous membranes — including SYMBLEPHARON (conjunctival adhesion to the eyelid) from ocular involvement. This is why MMP patients are referred to ophthalmologists — ocular scarring can cause blindness.