A female presented with a skin lesions all over the body which shows positive 'bulla spread sign'. It is characteristic of:

Pemphigus vulgaris is characterized by cutaneous and mucosal blisters. On application of tangential pressure on normal skin results in formation of new bulla (Nikolsky sign) or if applied to pre-existing bulla results in the spread of bulla (bulla spread sign). Cutaneous lesions predominantly present on face, trunk, axillae, groins, and scalp. Ref: Illustrated Synopsis Of Dermatology & Sexually Transmitted Diseases By Khanna, 3rd edition, Page 64.