Bullous pemphigoid, or BP, is an autoimmune blistering skin disease. BP is a serious condition with significant associated morbidity and mortality. Widespread tense and hemorrhagic blisters, skin erosions and severe itching cause patients a great deal of distress and pain.
Untreated, BP may be a self-limiting disease in a proportion of patients with periods of spontaneous remissions and exacerbations. In most patients who are treated, BP remits within 1.5-5 years, but may recur once medication is stopped. Patients are often admitted to hospital for initial treatment. The estimates of admission rates for patients with BP vary, but they are generally high, thus representing a significant burden and cost to the healthcare systems. The severity of symptoms and lesions in BP make treatment mandatory. Corticosteroids are often administered and frequent hospital visits are needed for dose adjustments.
Older age at onset and frail general condition are poor prognostic factors. Many available treatments are associated with toxicity and may be poorly tolerated in patients with BP. It is thought that, in the elderly population, corticosteroid treatment contributes to the high mortality rate. This is due, at least in part, to the significant adverse events associated with the use of steroids, such as hypertension, diabetes, infections and osteoporosis. Management of these conditions can be difficult and their treatment represents a significant burden. Therefore, the avoidance of systemic corticosteroids in this vulnerable group of patients is highly desirable and a safer, effective alternative is needed.
Treatment should aim to control symptoms with minimum adverse effects where possible. Options are broadly divided into anti-inflammatory drugs, immunosuppressive or immunomodulating drugs, and procedures that aim to remove circulating pathogenic antibodies and inflammatory mediators. Corticosteroids are the most commonly used anti-inflammatory drugs given for treatment of BP. They are administered systemically, for example prednisolone, or topically for very potent steroids such as clobetasol. Anti-inflammatory antibiotics such as tetracyclines are used as well.
Long-term use of potent steroids is associated with several adverse effects such as severe skin atrophy, osteoporosis, diabetes, glaucoma, cataract formation, weight gain, and psychologic disturbances. Azathioprine and methotrexate are still commonly used to treat BP. Intravenous immunoglobulins have been used as immunomodulatory agents in BP as well as other auto immune blistering skin diseases.
The choice of treatment depends on the individual patient’s circumstances especially the severity of the BP and presence of comorbidities. All of these treatment options have limited applicability due to reasons associated with efficacy, safety or both. Thus, there exists a need for a safe and effective therapy for BP patients.