A nurse is assessing multiple skin lesions on a patient with pemphigus vulgaris. The skin is easily rubbed off when the nurse applies slight friction. This best describes which of the following?
• Nikolsky's sign is positive when slight friction or rubbing causes exfoliation of the skin
• A positive Nikolsky's sign is a hallmark of pemphigus vulgaris, a chronic autoimmune disease that causes painful blisters
• Blumberg's sign is the presence of rebound tenderness in the abdomen and is indicative of peritonitis
• Murphy's sign is indicative of cholecystitis
• O'Connor's sign does not exist