The incidence of cyclic vomiting syndrome in children: population-based study.

OBJECTIVE: Cyclic vomiting syndrome (CVS) is characterized by severe recurrent episodes of vomiting in an otherwise healthy child. Currently, there is no population data on the incidence of CVS. The aim of this study was to determine the incidence of CVS and to define the clinical characteristics of the condition at diagnosis.

METHODS: Each pediatrician on the island of Ireland was surveyed on a monthly basis from January 1, 2005 to December 31, 2005 by the Irish Pediatric Surveillance Unit (IPSU) and was asked to report any incident cases of CVS according to the criteria outlined by the First International Symposium on CVS. Subsequently, data on demographics and clinical features were collected anonymously from the reporting pediatricians.

RESULTS: Eighty-nine percent (1,647 of 1,848) of the surveillance cards were returned, reporting 41 valid cases of CVS. The incidence of CVS in Ireland was 3.15/100,000 children per annum for 2005 (95% confidence interval [CI] 2.19-4.11). The median age at diagnosis of CVS was 7.42 yr (range 1.8-15 yr). The median age at onset of CVS was 4 yr (range 0.5-14 yr) with 46% (19 of 41) of children having an onset at or before the age of 3 yr. The median number of episodes of CVS per child per year was eight (range 3-52); the median duration of an episode was 24 h (range 1 h to 5 days). Of school-age children, 85% (22 of 26) had missed school in the previous year due to CVS and 44% (18 of 41) were admitted to hospital for supportive treatment or investigation of CVS.

CONCLUSION: CVS is a relatively common condition in pediatric patients, with an incidence comparable to other major gastrointestinal diseases of childhood, such as Crohn's disease. The onset of pediatric CVS is generally early in childhood and this disease causes significant morbidity in the majority of those affected.