Systemic autoinflammatory disorders are hereditary diseases with symptoms of acute inflammation and a rise in serum acute phase proteins as a consequence, but with no signs of autoimmunity. By the end of the 1990s, four types of hereditary periodic fever had been described in the medical literature: familial Mediterranean fever, hyperimmunoglobulinemia D with periodic fever syndrome (HIDS), tumour necrosis factor receptor-associated periodic fever syndrome (TRAPS) and Muckle-Wells syndrome. Since then, the number of diseases classified as systemic autoinflammatory disorders has increased to eight. In patients of Nordic descent, cases of HIDS and TRAPS have been reported. We provide an overview of the genetic background and main clinical aspects of the different autoinflammatory disorders, with an emphasis on TRAPS.