<prompt> A 28-year-old patient has multiple grouped papulovesicular lesions on both elbows, knees buttocks and upper back associated with severe itching. The most likely diagnosis isPemphigus vulgarisBullous pemphigoidDermatitis herpetiformisHerpes Zoster  <response>: Look for itching Severe itchingPapulovesicular lesionOn extensors knees, elbows, scapular region upper back, buttock.Age 28 years 