This controlled multi-center randomized clinical trial, with direct individual benefit, will compare efficacy and safety of two strategies in non-localized BP care: a combined regimen using initial superpotent topical steroids associated with methotrexate for 4 weeks followed by methotrexate alone for 8 months and superpotent topical steroids alone maintained 9 months (current standard of care). The expected result is an equivalence between the two compared strategies in terms of safety and efficacy, MTX monotherapy during the maintenance phase being easier to manage and therefore associated with better compliance than topical steroids with less cutaneous side effects and most cost-effective.