Chicken pox

Chicken pox is a highly contagious illness caused by primary infection with varicella zoster virus (VZV). It usually starts with vesicular skin rash mainly on the body and head rather than at the periphery and becomes itchy, raw pockmarks, which mostly heal without scarring.

By the time Tom Riddle was eleven, Billy Stubbs and Eric Whalley had chicken pox.

Appearances

 * Harry Potter and the Half-Blood Prince