* This is the Professional Version. *
Bullous pemphigoid is a chronic autoimmune skin disorder resulting in generalized, pruritic, bullous lesions in elderly patients. Mucous membrane involvement is rare. Diagnosis is by skin biopsy and immunofluorescence testing of skin and serum. Topical and systemic corticosteroids are used initially. Most patients require long-term maintenance therapy, for which a variety of immunosuppressants can be used.
Bullous pemphigoid occurs more often in men > 60 yr but can occur in children. IgG autoantibodies bind to certain hemidesmosomal antigens (BPAg1, BPAg2), resulting in the activation of complement to form a subepidermal blister.
No cause has been proved; however, the following have been suggested:
It is not clear whether cancer is associated with bullous pemphigoid.
Pruritus is the first symptom. Skin lesions may not develop for several years, but often characteristic tense bullae develop on normal-appearing or erythematous skin in the flexural and intertriginous areas. Bullae usually do not rupture, but those that do often rapidly heal. Polymorphic, annular, dusky-red, edematous lesions, with or without peripheral vesicles, can occur. Rarely, small blisters develop on the mucosa. Leukocytosis and eosinophilia are common, but fever is rare. The Nikolsky sign, where upper layers of epidermis move laterally with slight pressure or rubbing of skin adjacent to a blister, is negative.
If blisters develop, bullous pemphigoid needs to be differentiated from pemphigus vulgaris, a blistering disorder with a worse prognosis; differentiation is usually possible using clinical criteria (see Pemphigus Vulgaris and see Distinguishing Pemphigoid From Pemphigus Vulgaris).
Distinguishing Pemphigoid From Pemphigus Vulgaris
Test results help differentiate bullous pemphigoid from pemphigus vulgaris, linear IgA disease, erythema multiforme, drug-induced eruptions, benign mucous membrane pemphigoid, paraneoplastic pemphigoid, dermatitis herpetiformis, and epidermolysis bullosa acquisita. If bullous pemphigoid is suspected, skin biopsy is done for histology and direct immunofluorescence testing. Samples from in and around the lesion itself are often used for histology, but samples of uninvolved skin (often about 3 mm from the edge of a lesion) are used for direct immunofluorescence results. Serum is tested for IgG antibodies to BPAg1 and BPAg2 using an enzyme-linked immunosorbent assay (ELISA). The blister in bullous pemphigoid is subepidermal, often containing many neutrophils and eosinophils. Circulating IgG autoantibodies are present in about three fourths of patients.
High-potency topical corticosteroids (eg, clobetasol 0.05% cream) should be used for localized disease and may reduce the required dose of systemic drugs. Patients with generalized disease often require prednisone 60 to 80 mg po once/day, which can be tapered to a maintenance level of ≤ 10 to 20 mg/day after several weeks. Most patients achieve remission after 2 to 10 mo. If long-term therapy is necessary, a new blister every few weeks does not require increasing the prednisone dose.
Bullous pemphigoid occasionally responds to a combination of tetracycline or minocycline and nicotinamide. Other treatment options include monotherapy with dapsone, sulfapyridine, or erythromycin. IV immune globulin has been used occasionally. For patients with generalized and recalcitrant disease, and sometimes to decrease corticosteroid dose in chronic disease, immunosuppressants such as azathioprine, cyclophosphamide, mycophenolate mofetil, rituximab, and cyclosporine may be used.
Bullous pemphigoid usually affects men > 60 yr and is autoimmune and idiopathic.
Pruritus may precede development of a rash by years, and mucous membrane involvement is rare.
Biopsy the skin for histology and immunofluorescence testing and measure circulating autoantibodies.
Treat patients with high-potency topical corticosteroids when possible to avoid or minimize use of systemic corticosteroids.
* This is the Professional Version. *