Background. PFAPA syndrome is the most common cause of recurrent fever in children. Despite the long history of the disease, the etiology and pathogenesis of the disease have not been definitively established. Aim. Analysis of the scientific medical literature on PFAPA syndrome (Marshall syndrome) with the presentation of personal clinical observation. Material and methods. An analysis of the medical literature devoted to the problem has been performed. A clinical case of a child with Marshall syndrome is presented. Results and discussion. The nature of the disease is associated with cytokine dysfunction and dysregulation of the inflammasome, which allows it to be classified as an autoinflammatory syndrome. The diagnosis of the disease is based on clinical and history criteria, the specificity of which has been questioned in recent years; new diagnostic criteria are now proposed. Despite the absence of doubleblind randomized clinical trials, there is a wealth of experience with therapeutic approaches to PFAPA syndrome, includingВЕСТНИК СОВРЕМЕННОЙ КЛИНИЧЕСКОЙ МЕДИЦИНЫ 2021 Том 14, вып. 479ИЗ ПРАКТИЧЕСКОГО ОПЫТАthe administration of glucocorticoids, colchicine, and tonsillectomy. Our clinical example illustrates the problem of late diagnosis of PFAPA syndrome, the effectiveness of using glucocorticoids to control attacks as firstline therapy, and the need for different therapeutic approaches and differential diagnosis in complicated cases of monogenic autoinflammatory diseases. Conclusion. PFAPA syndrome is the most prevalent hereditary periodic fever syndrome. The exact epidemiology of the disease has not been studied, but it is assumed that the number of diagnosed cases is significantly lower than the actual prevalence of the disease. Attempts to revise the diagnostic criteria of PFAPA syndrome are currently underway. Despite the lack of randomized doubleblind clinical trials to date, therapeutic strategies continue to improve.