Mucous membrane pemphigoids are a group of chronic autoimmune blistering diseases of the chorioepithelial or dermoepidermal junction, which are characterized by predominant or exclusive mucosal involvement.¹⁾ Mucous membrane pemphigoids primarily affect older patients, typically those aged 60–80 years.²⁾ Mucosal involvement includes the oral, nasopharyngeal, laryngopharyngeal, genital, esophageal, tracheal, anal, and ocular mucosal membranes. Additionally, skin lesions may also be present, although they are typically mild and are observed in approximately 30% of patients.²⁾ Mucous membrane pemphigoids are characterized by scarring resulting from initial inflammation, leading to significant morbidity, including pain, malnutrition, and corneal blindness. In nonagenarians, the management of mucous membrane pemphigoid becomes more complex owing to the age-related physiological changes, comorbidities, and potential polypharmacy interactions. Herein, we report a case of an old patient who presented with painful buccal erosions and was diagnosed with mucous membrane pemphigoid that was successfully treated with topical corticosteroids.

A 92-year-old male patient presented with a 6-month history of oral erosion that had resulted in feeding disorders and subsequent weight loss. His medical history included hypertension, atrial fibrillation, and dyslipidemia. Clinical examination revealed post-blistering erosions of the left buccal mucosa associated with palatal erosion (Fig. 1). The patient did not present any other mucosal or skin lesions. A skin biopsy revealed a cleavage between the epidermis and dermis with a few interstitial eosinophils present (Fig. 2). Direct cutaneous immunofluorescence of the biopsy revealed linear immunoglobulin G (IgG) and C3 deposits along the basement membrane. Laboratory test results were negative for antibodies against BP180, BP230, type VII collagen, and laminin 332. Immunoblotting studies of the skin extract and indirect immunofluorescence of salt-split skin yielded negative results. Clinical, histological, and immunological findings were consistent with a diagnosis of mild mucous membrane pemphigoid because the clinical involvement was limited to one site. As the Consensus Conference¹⁾ indicates that topical treatments can be introduced initially, the patient was prescribed clobetasol propionate cream. The lesions healed completely within 3 months of daily application, allowing the resolution of pain and recovery of optimal oral feeding. No recurrence was observed after 1 year of follow-up.

The symptoms and complications of mucous membrane pemphigoid can substantially impact the quality of life of patients living with the disease and can cause difficulties in eating, ultimately leading to malnutrition in some cases, as observed in our patient. Scar formation is a characteristic feature of mucous membrane pemphigoid, which can result in major disabilities (e.g., blindness and esophageal, anal, and vaginal stenosis) and life-threatening situations (e.g., laryngeal stenosis leading to respiratory failure).

Mucous membrane pemphigoid is characterized by autoantibodies directed against various antigens of the dermoepidermal junction (i.e., BP180, laminin 332, type VII collagen, α6β4 integrin).²⁾ Despite the recognition of multiple antigens targeted by autoantibodies and the use of various detection techniques (e.g., enzyme-linked immunosorbent assay [ELISA], immunoblot studies of skin extract, salt-split skin indirect immunofluorescence, and biochip technology), approximately one-third of the patients with mucous membrane pemphigoid do not have detectable autoantibodies, as in our patient.^3,4) According to the Consensus Conference,¹⁾ a diagnosis of mucous membrane pemphigoid is established based on the clinical presentation along with the detection of anti-dermoepidermal junction autoantibodies on direct immunofluorescence, direct immunoelectron microscopy, or serological tests (e.g., ELISA, immunoblotting).^2,5) Direct immunofluorescence is the major diagnostic test, which has the highest sensitivity for the diagnosis of mucous membrane pemphigoid.⁵⁾

For mild/moderate mucous membrane pemphigoid, dapsone, methotrexate, tetracyclines, and/or topical corticosteroids are recommended as the first-line treatment.⁵⁾ Considering the advanced age and potential frailty of our patient, we opted for a topical treatment. High-potency topical corticosteroids led to complete remission in our patient within 3 months, indicating that less invasive treatments can be more beneficial in geriatric patients with mild/moderate mucous membrane pemphigoid. Such a strategy limits the risk of potentially life-threatening adverse events associated with systemic therapies in patients of advanced age.

In conclusion, mucous membrane pemphigoid is a rare autoimmune disease that predominantly affects the mucous membrane and frequently affects the oral mucosa. Recognizing this condition is crucial due to its potential to reduce the quality of life (e.g., oral pain), especially among older patients.