Distribution of the whole bullous pemphigoid (BP) patients (n = 95) (A) and of BP patients without (n = 77) (B) and with (n = 18) (C) mucosal involvement according to total BP Disease Area Index (BPDAI) values at the time of diagnosis. In the whole BP group and in the subgroup of BP without mucosal involvement, the number of BP included decrease when the values of the BPDAI increased, whereas BP patients with mucosal involvement were evenly distributed. Comparison of the cumulative distribution by the Kolmogorov–Smirnov test showed significant difference between BP patients with (C) and without (B) mucosal involvement (D = 0.6154; P = 0.008).