Autoinflammatory syndromes/fever syndromes
Hereditary periodic (fever) syndromes, also called autoinflammatory syndromes, are characterized by relapsing fever and additional manifestations such as skin rashes, mucosal manifestations, or joint symptoms. Some of these disorders present with organ involvement and serological signs of inflammation without fever. There is a strong serological inflammatory response with an elevation of serum amyloid A (SAA), resulting in an increased risk of secondary amyloidosis. There are monogenic disorders (familial mediterranean fever (FMF), hyper-IgD-syndrome (HIDS), cryopyrin-associated periodic syndromes (CAPS), "pyogenic arthritis, acne, pyoderma gangrenosum" (PAPA), and "pediatric granulomatous arthritis (PGA) where mutations in genes have been described, which in part by influencing the function of the inflammasome, in part by other means, lead to the induction of the production of IL-1β. In "early-onset of enterocolitis (IBD)", a functional IL-10 receptor is lacking. Therapeutically, above all, the IL-1 receptor antagonist anakinra is used. In case of TRAPS and PGA, TNF-antagonists (etanercept) may also be used; in FMF colchicine is first choice. As additional possible autoinflammatory syndromes, PFAPA syndrome (periodic fever with aphthous stomatitis, pharyngitis and adenitis), Schnitzler syndrome, Still's disease of adult and pediatric onset, Behçet disease, gout, chronic recurrent multifocal osteomyelitis (CRMO) and Crohn's disease also are mentioned.