You observe sub-epithelial clefting with complement and IgG deposits at the basement membrane. To which specialist would you refer?

Correct answer: A. Ophthalmologist

• A. Correct. This histologic/immunofluorescence picture (subepithelial clefting with linear IgG/complement at the basement membrane) is diagnostic of mucous membrane pemphigoid (MMP). Ocular involvement (symblepharon, scarring) can progress to blindness, so urgent ophthalmology referral is critical.
• B. While dermatology may be involved in management of MMP, the most urgent/specific referral given the risk of blindness is ophthalmology.
• C. Cardiology is unrelated to this autoimmune mucocutaneous condition.
• D. ENT is not the priority referral; ocular involvement risking blindness makes ophthalmology the key urgent referral.

Note: This is mucous membrane pemphigoid (MMP/cicatricial pemphigoid). Ocular involvement can cause blindness.