Management of Coexisting Bullous Pemphigoid and Psoriasis: A Review.

Psoriasis in an immune-mediated inflammatory disease and is associated with increased risk of various comorbidities, especially autoimmune bullous diseases. However, the optimal management of coexisting psoriasis and bullous pemphigoid (BP) is not known. A systematic search revealed 64 articles, including 84 patients with such cases. For those with mild BP activity and clear triggers, discontinuation of culprit agents and using topical corticosteroid was the most common treatment. Systemic corticosteroids and methotrexate were most widely used for moderate to severe diseases, but flare up of BP and psoriasis was common when the immunosuppressants were tapered. Azathioprine and cyclosporine were less often used but appeared to be reasonable alternatives. Antibiotics with anti-inflammatory properties and vitamins (niacinamide and acitretin) exert modest effect. Effects of novel biologics approved for use in psoriasis, such as etanercept, ustekinumab, secukinumab, and ixekizumab, on coexisting BP and psoriasis remain controversial because new onset of BP has been reported. Though rituximab and dupilumab may be beneficial for BP, they might sometimes induce or aggravate psoriasis. Despite the presence of many case reports or case series, high-quality studies are lacking and are needed to better clarify the optimal treatment strategy for coexisting BP and psoriasis. Based on current evidence, we suggest physicians evaluate the severity of BP and identify if there is any modifiable trigger factor, such as UV or biologics. After removing trigger factors, for patients with mild BP, topical corticosteroid may be considered first. Systemic immunosuppressants such as corticosteroid and methotrexate remained the most popular choices for more extensive cases followed by azathioprine and cyclosporine, but the dose should be slowly tapered to prevent psoriasis or BP flare up.