Explained: The disorder paralysing Justin Bieber's face, Ramsay Hunt Syndrome

Ramsay Hunt syndrome (RHS), which has forced singer Justin Bieber to cancel his world tour, is a rare and painful complication of the virus that causes shingles and chickenpox. – Photos: Justin Bieber/Instagram

Ramsay Hunt syndrome (RHS), which has forced singer Justin Bieber to cancel his world tour, is a rare and painful complication of the virus that causes shingles and chickenpox.

RHS was discovered in 1907 by the neurologist of the same name. It is a rare neurological disorder that can inflame and paralyse the facial nerve and cause a painful rash around the ear or mouth.