A 30–year–old male had severely itchy papulovesicular lesions on extremities, knees, elbows and buttocks for one year. Direct immunofluorescence staining of the lesions showed IgA deposition at dermo epidermal junction. The most probable diagnosis is –
Pemphigus vulgaris
Bullous pemphigoid
Dermatitis herpetiformis
Nummular eczema