Nikoisky's sign is positive in
Nikolsky's sign : Development of an erosion on surrounding normal skin following shearing pressure .Though this sign is characteristic for pemphigus group of disorders is not specific and can be elicited in burns and other skin disorders. Page no. 281 Reference IADVL's concise textbook of dermatology
Pemphigus
Dermatitis herpatiformis
Pemphigoid
Rubella
Vestibulobullous disorders