Variable expression of vasculitis in siblings with familial Mediterranean fever

Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by recurrent and self-limited attacks of serosal inflammation with abdominal pain, chest pain, and arthritis usually accompanied by fever. Different vasculitides such as polyarteritis nodosa (PAN) and Henoch-Schonlein syndrome (HSS) may be associated with FMF. We report two sisters of a Turkish family with FMF who developed distinct vasculitides. The younger sister developed severe PAN with perirenal hematoma at the age of 13 years, the older sister presented with severe HSS and acute renal failure at the age of 19 years. Neither sister developed amyloidosis until the age of 30 years. This observation suggests that early events in the pathogenesis of PAN and HSS are generally quite similar.