Henoch-Schönlein purpura (HSP) is a rare condition in which blood vessels become inflamed. It typically results in a rash and joint and tummy pain.

HSP is caused by a problem with your immune system, possibly as a result of a previous infection.

It has been known to occur after a bacterial or viral infection of the throat, airways or lungs (respiratory tract infection).

HSP cannot be spread from person to person and doesn’t usually run in families.