Bullae are elevated, fluid-filled blisters ≥ 10 mm in diameter.
(Synonyms of mucous membrane pemphigoid that are no longer used include cicatricial pemphigoid, ocular cicatricial pemphigoid, and benign mucous membrane pemphigoid.)
Oral mucous membrane pemphigoid and ocular mucous membrane pemphigoid are typical, but other mucosal sites and the skin (usually of the head and upper trunk) may be involved (1). Older adults are most often affected, women more than men.
Mucous membrane pemphigoid (MMP) is characterized by subepithelial lesions caused by autoantibodies against molecules of epithelial basement membranes. The target molecules lie deeper than those of bullous pemphigoid. Several autoantibodies have been identified, including those against BPAG2, laminin-332, and type VII collagen. Antibodies to beta-4 integrin have been identified in generalized MMP and ocular MMP, and antibodies to alpha-6 integrin have been identified in oral MMP.
General reference
1. Rashid H, Lamberts A, Borradori L, et al: European guidelines (S3) on diagnosis and management of mucous membrane pemphigoid, initiated by the European Academy of Dermatology and Venereology - Part I. J Eur Acad Dermatol Venereol 35(9):1750-1764, 2021. doi: 10.1111/jdv.17397
Diagnosis of Mucous Membrane Pemphigoid
Skin biopsy and direct immunofluorescence
Prevalent mucosal involvement and scarring lesions help distinguish MMP from bullous pemphigoid. Diagnosis of mucous membrane pemphigoid is supported by lesion biopsy and direct immunofluorescence (1). Linear basement membrane deposits may include IgG, IgA, and C3. Serum autoantibodies tend to be absent or at low titer.
Diagnosis reference
1. Schmidt E, Rashid H, Marzano AV, et al: European Guidelines (S3) on diagnosis and management of mucous membrane pemphigoid, initiated by the European Academy of Dermatology and Venereology - Part II. J Eur Acad Dermatol Venereol 35(10):1926-1948,2021. doi: 10.1111/jdv.17395
Treatment of Mucous Membrane Pemphigoid
For severe disease, systemic immunosuppression
Treatment of mucous membrane pemphigoid is similar to that for bullous pemphigoid1).
Treatment reference
1. Schmidt E, Rashid H, Marzano AV, et al: European Guidelines (S3) on diagnosis and management of mucous membrane pemphigoid, initiated by the European Academy of Dermatology and Venereology - Part II. J Eur Acad Dermatol Venereol 35(10):1926-1948, 2021. doi: 10.1111/jdv.17395
Prognosis for Mucous Membrane Pemphigoid
Mucous membrane pemphigoid progresses slowly, rarely remits spontaneously, and often responds incompletely to treatment. Depending on the site affected, serious sequelae may include ocular damage and blindness, airway erosions and destruction, and strictures of the esophagus or anogenital regions. Patients with anti-laminin-332 MMP have an increased risk of internal cancer; if this form is suspected (eg, by immunofluorescence results), patients should be screened for cancers common to their age and sex.
Key Points
Mucous membrane pemphigoid is a group of rare chronic autoimmune disorders causing waxing and waning bullous lesions of the mucous membranes, often with scarring.
Diagnose using skin biopsy and direct immunofluorescence.
