Periodic fever syndromes are rare diseases, meaning they affect fewer than 5 out of 10,000 people. They are usually hereditary  and may be caused by a change to the genetic recipe (DNA) of the non-specific innate immune system that causes the system to be switched on even without invaders to fight. Periodic fever syndromes include cryopyrin-associated periodic syndromes (CAPS), familial Mediterranean fever (FMF), tumour necrosis factor receptor associated periodic syndrome (TRAPS) and hyperimmunoglobulinemia D syndrome/ Mevalonate kinase deficiency (HIDS/MKD).
The symptoms involve the repeated occurrence of fever lasting more than 24-hours and are often accompanied by rashes and joint pain Other symptoms can be present and sometimes further damage may occur due to the effects of continuous (chronic) inflammation.
Diagnosis of CAPS, FMF, TRAPS, or HIDS/MKD can be a complicated process. This is because these diseases occur only rarely, and have symptoms common to many other diseases. Thus, a diagnosis may involve several diagnostic tests before the true cause or condition is identified. It’s also important to know that, in order to arrive at the diagnosis, the clinical specialist must rule out many other possible conditions Some patients may have relatives, parents, or even siblings with the same autoinflammatory disease.
1. Ciccarelli F, De Martinis M, Ginaldi L. Curr Med Chem 2014; 21: 261–269.