Introduction
PFAPA, PFAPA syndrome, autoinflammatory diseases, heredity, pharyngitis
CERVICAL ADENITIS, FAMILIAL MEDITERRANEAN FEVER, PERIODIC FEVER, AUTOINFLAMMATORY DISEASE, PFAPA SYNDROME, DISEASE, APHTHOUS STOMATITIS, PERIODIC FEVER SYNDROME, SYNDROME, PHARYNGITIS, IDIOPATHIC DISEASE
Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis syndrome (PFAPA) is the most common periodic fever syndrome in childhood. In the terms of aetiology, it is considered to be an idiopathic disease. A polygenic pattern of inheritance is suspected, probably in combination with some epigenetic factors. The incidence is 2.3 per 10,000 children below the fifth year of life (PFAPA belongs to autoinflammatory diseases with probably oligogenic or polygenic heredity. The pathomechanism is still not known, but some of the pathogenic mutations in heterozygous state as well as variants of uncertain significance in the genes typically affected in familial Mediterranean fever (Ketotifen is the first-generation antihistamine with proven immunomodulatory effects. According to some studies it reduces the production of IL-1β and some proinflammatory chemokines and modulates the T cell response. The positive effect of ketotifen on reduction of frequent attacks was also demonstrated in a case series of PFAPA patients (In our trial, we aimed to analyse the selected clinical and laboratory characteristics of the children fulfilling the clinical criteria for PFAPA syndrome and assessed the possible preventive role of ketotifen on the onset of flares and disease activity.