 Included patients with bullous pemphigoid will be followed for 1 year. Baseline and 6 follow-up visits are planned to record disease activity, treatment and laboratory monitoring modalities and to collect blood samples for ancillary studies. Clinical data recorded at baseline are gender, age and associated medical conditions neurological disorders: dementia, stroke, Parkinsons disease, multiple sclerosis; malignancy; other diseases. Baseline clinical evaluation includes the number of daily new blisters for 3 consecutive days, localization of skin or mucous membrane blisters and erosions and BPDAI bullous pemphigoid disease area index. Extensive bullous pemphigoid is defined as the occurrence of at least 10 new daily blisters. The first-line treatment used will be recorded superpotent topical CS, i.e. clobetasol propionate cream, 20-30g per day; methotrexate; other systemic therapy. At each visit, the presence of pruritus, erythematous or eczematous or urticarial plaques, and the number of new daily blisters are recorded and a BPDAI bullous pemphigoid disease area index is calculated. Topical and systemic treatments for bullous pemphigoid are recorded at each visit, as the occurrence and date of relapse, which eventually occurred. Relapse is defined as the reappearance of 3 new daily blisters along with pruritus andor erythematous, eczematous or urticarial plaques. 