['Tonsillectomy has recently been suggested as an effective treatment for PFAPA syndrome but little is known about its long-term efficacy. We compared the clinical features and the long-term outcome of a large cohort of patients with PFAPA syndrome treated with tonsillectomy or with standard medical treatment.', 'We conducted a retrospective study on patients with PFAPA syndrome followed at a tertiary care centre from January 1993 to August 2010. Clinical characteristics and laboratory parameters were evaluated at onset and during the follow-up. Disease outcomes of patients who underwent tonsillectomy and of those treated with medical therapy (NSAIDs, prednisone) were compared. Clinical remission on medication (CRM) was considered the persistence of fever attacks which were well controlled by medical therapy, clinical remission (CR) was defined as the absence of fever attacks, without any treatment, for more than 12 months.', '275 patients with PFAPA syndrome, 59.6% males, aged 27.9 months at onset and followed for mean 54.5 months, entered the study. CR was reported in 59.6% of the patients and was significantly less frequent in those with positive family history for PFAPA (46.4% vs. 66.1%, p=0.003). 27/41 patients (65.9%), responded to tonsillectomy and this result was comparable with that observed in those treated with medical therapy (59.1%, p=0.51). Disease duration, age at remission or presence of associated symptoms were not significantly different in both groups. No predictors of tonsillectomy failure were found.'] Is tonsillectomy efficacy in children with PFAPA syndrome comparable to the standard medical treatment : a long-term observational study?