Oral Manifestations of Autoimmune Blistering Diseases

History
Autoimmune blistering skin diseases generally have an insidious onset. The following may be noted on history:

When oral lesions are present, they invariably are symptomatic, varying from mild to unbearable pain.
Patients with mucous membrane pemphigoid often complain of spontaneous gum bleeding.
Lesions start to surface in the oral cavity by approximately 6 months prior to the skin lesions in most patients with pemphigus vulgaris.
In some patients who have oral manifestations of autoimmune blistering diseases, the symptoms are so severe that they prevent them from proper dietary intake, resulting in severe malnutrition.
In patients who have rectal involvement, pain and bleeding could be early symptoms.
In patients with laryngeal involvement, hoarseness could be an early symptom.
Intractable hemorrhagic stomatitis is highly suggestive of paraneoplastic pemphigus.

Physical
Oral manifestations of autoimmune blistering diseases generally can affect any area of the oral cavity, including the gingiva, palate, buccal, tongue, floor of the mouth, and pharynx. In the pemphigus disease group, the blisters are broken easily; therefore, they rarely are observed clinically. Instead, erosions and superficial ulcers more likely are observed. In the pemphigoid disease group, because the blisters are situated deeply, they are more likely to be observed intact clinically. Note the following:

In pemphigus vulgaris, oral lesions occur in most patients. In most patients, the oral mucous membranes are affected within 6 months of disease onset. In some patients, it remains exclusively an oral disease for months or years before generalized skin disease develops. Typically, small blisters rapidly evolve into erosions covered with white-yellow pseudomembranes. All areas of oral mucous membranes, gingiva, buccal, palate, tongue, and floor of the mouth can be affected (see the image below). A subgroup of patients with pemphigus vulgaris does not develop skin disease.
Oral manifestations, including blisters, hemorrhagic erosions, and crusts, are shown on a patient with pemphigus vulgaris.
Pemphigus foliaceus is predominantly a skin disease. Oral or other mucous membrane involvements are very rare. In skin, desmoglein-3 is present predominantly in the lower layers of epithelial cells. By contrast, the layers of desmoglein-3 are present throughout the upper and lower layers of epithelium in the oral mucous membrane. Thus, the autoantibodies of patients with pemphigus foliaceus, which exclusively target desmoglein-1, are unable to break down the adherence of the upper layers of epithelium of oral mucosa, which is protected by the presence of desmoglein-3.
In paraneoplastic pemphigus, oral lesions, which are invariably present in this disease, can precede, follow, or appear at the same time of neoplasm discovery. Severe mucositis with hemorrhagic blisters, erosion, or ulceration can be observed in various oral mucosae. Lesions at the vermilion border almost always are present.
In patients with bullous pemphigoid, oral lesions rarely are observed. If present, they usually are mild and consist of small blisters or erosions. In one patient with bullous pemphigoid and hemophilia, extensive bullous lesions occurred in the mouth, along with substantial bleeding.
In the rare occurrence of lichen planus pemphigoides, small blisters and flat, linear, white, netlike striae that characterize lichen planus can occur in oral mucous membranes.
With linear IgA bullous dermatosis (of adult and children), the oral lesions, rarely present, are similar to that of bullous pemphigoid or can mimic aphthaelike ulcers.
Oral lesions in epidermolysis bullosa acquisita commonly are observed. The lesions are deep-seated blisters, erosions, and ulcers, sometimes hemorrhagic. Milia are clinically observed.
Regarding mucous membrane pemphigoid, the oral mucous membrane is the most frequently affected site in this heterogeneous group of diseases, followed by ocular, skin, nasal, genital, pharyngeal, esophageal, laryngeal, and anal mucous membranes. Approximately 50% of patients with mucous membrane pemphigoid have oral mucosal lesions, as shown in the image below.