Screening for Adrenal Insufficiency During Dermocorticoid Reduction in Bullous Pemphigoid (BP)

Inclusion Criteria: * Male or female at least 18 years of age * BP diagnosis with at least 3 of the following 4 criteria: * Age greater than 70 years * Absence of mucosal involvement * Absence of atrophic scarring * No predominance of head and neck * Skin biopsy with subepidermal cleavage and : * FD with Ig and/or C3 deposits along the basement membrane * And/or positive serum anti-BP180 and/or anti-BP230 antibodies * Treated with clobetasol propionate, with or without background treatment (methotrexate, mycophenolate mofetil, IV Ig, omalizumab, rituximab) * Treatment with clobetasol propionate 0.05%, 20 to 40 g per application, twice a week for at least one month * Affiliated to a social security regimen ( without AME) * Free, informed and expressed consent (confirmed in writing) Exclusion Criteria: * Old or ongoing adrenal insufficiency * Systemic corticosteroid therapy of more than 1 month in the previous 3 months and/or more than 3 months in the previous 12 months, or in the 7 days prior to the cortisol test * Immuno-induced bullous pemphigoid (anti-PD1, PDL1 and/or anti-CTLA4) * Impossible to perform a blood test between 7:30 and 8:30 am