This is an autoimmune skin disease, and manifests as tense, cutaneous bullae overlying an erythematous base.  Sometimes, the bullae are lacking and patients present with pruritic plaques. This disease is more common in elderly patients and affects males and females equally.  Common sites of involvement include the  flexor surfaces of the arms and legs, the axilla, the groin and the lower abdomen.  Unlike some forms of pemphigus, Nikolsky’s sign is absent and involvement of the mucous membranes occurs infrequently.  There is an increased incidence of BP in patients with underlying diabetes mellitus, rheumatoid arthritis, vitiligo, pernicious anemia, multiple sclerosis, psoriasis, lichen planus, and pemphigus vulgaris.  Common medications associated with drug induced pemphigoid include furosemide, captopril, phenytoin and ciprofloxacin.

Autoantibodies against anchoring filaments causes a breakdown of the dermal-epidermal junction with resultant skin fragility and blisters. Direct immunofluorescence of biopsy specimens reveals linear C3 and IgG deposition at the epidermal basement membrane. Clinically, the diagnosis is suspected in cases of  blistering skin disease when there is a lack of atrophic scars, unaffected mucous membranes, sparing of the head and neck, and patient age greater than 70 years old.

Therapy includes the use of ultra potent topical corticosteroids (colbetasol proprionate cream 0.05% twice daily for prolonged periods followed by a slow taper) which have replaced systemic steroids (prednisone1 mg/kg/day) with or without immunosuppressants (azathiprine, methotrexate, mycophenolate mofetil, or tetracyclines).  Consultation with a dermatologist may be required.