Non-thrombocytopenic purpura in familial Mediterranean fever-comorbidity with Henoch-Schönlein purpura or an additional rare manifestation of familial Mediterranean fever?

Henoch-Schönlein purpura is a relatively common vasculitis mainly affecting children. It is characterized by purpuric skin rash, abdominal cramping, and haematuria. Skin biopsies taken from Henoch-Schönlein purpura lesions disclose perivascular IgA deposits. FMF is an autoinflammatory disease characterized by recurrent attacks of fever lasting 2-3 days which resolve spontaneously. Typical manifestations of the disease are peritonitis, pleuritis, pericarditis, arthritis and erysipelas-like erythema usually affecting the lower limbs. Over the years many reviews emphasized the clinical impression that Henoch-Schönlein purpura is more common among FMF patients than in healthy control population. In this review we summarize these reports and show that sometimes Henoch-Schönlein purpura associated with FMF differs from typical isolated Henoch-Schönlein purpura, and this is also the case with polyarteritis nodosa and SpA associated with FMF. It is suggested that these clinical manifestations (polyarteritis nodosa, Henoch-Schönlein purpura and SpA) should be considered to be associated with FMF as part of what we call FMF rather than as co-existing additional separate clinical entities.