Periodic fever syndromes--a clinical overview.

Most hereditary periodic fever syndromes known today have their onset in the first year of life. Only two, namely Familial Mediterranean Fever (FMF) and TNF-Receptor Associated Periodic Syndrome (TRAPS) occur later, with most patients having become symptomatic by their twentieth birthday. Therefore this review will concentrate on FMF and TRAPS, the latter being a very rare disease, while the former has become somewhat more common in mid-Europe as a result of migration.