IL-1β blockade in periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome: case-based review

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome and familial Mediterranean fever (FMF) are considered as inflammasome disorders associated with uncontrolled interleukin (IL)-1β production. Anti-IL1 agents are used in colchicine-resistant cases of FMF. Increase in pro-inflammatory mediators even between febrile attacks in PFAPA suggests that anti-IL1 treatment might be beneficial in these patients. We describe a child presenting with recurrent, self-limited febrile attacks at 1 year of age who was diagnosed as FMF being heterozygous for M694 V mutation. Her clinical findings were only controlled by the addition of canakinumab (2 mg/kg/8 week) to colchicine treatment. However, she developed typical PFAPA attacks during this treatment at 3 years of age. We conducted a literature search focusing on English articles with keywords including PFAPA, anakinra, canakinumab, and rilonacept. Five children and one adult patient with PFAPA were found and evaluated. Anakinra was reported to abort PFAPA attacks in children, while the adult patient first responded and then became resistant to anakinra. Canakinumab was effective in preventing febrile attacks in this patient. Failure of canakinumab to prevent PFAPA attacks in our case may arise from the differences in the pathophysiology of PFAPA and FMF. Thus, further experience with higher doses or shorter intervals of canakinumab is needed in children with PFAPA.