Nikolsky's sign

"'Nikolsky sign '" is a clinical dermatological sign. it is typical for pemphigus vulgaris and Toxic Epidermal Necrolysis / (Lyell's syndrome).

Types:
 * "'direct"': slight finger pressure on unaffected skin will cause skin efflorescence / erosion (this is due to The Binding of antibodies to desmosomes around the erosion).
 * "'indirect"': when pressing on the skin Bula, the bula spreads to the sides.