ABSTRACT
Cyclic vomiting syndrome (CVS) is a disorder of unknown etiology and pathogenesis characterized by recurrent, stereotypical episodes of vomiting with varying intervals of baseline or normal health in between.1 Various recent articles and proceedings of two international conferences on CVS published in the past decade have defined this disorder in detail and proposed potential mechanisms and treatment. These publications and symposia have provided critical steps in recognizing and understanding a disorder that has been poorly recognized and commonly misdiagnosed. Typical misdiagnoses include gastroenteritis, gastroesophageal reflux, food poisoning, recurrent ‘flu’ and eating disorders.2 Although CVS can begin in infancy, the median age of onset in our cohort is 4.8 years of age. As a measure of misdiagnosis, the median interval from onset of symptoms to the proper recognition is 1.9 years, during which time the child has suffered through about 15 or so episodes. Although the prevalence and incidence of CVS are unknown, current estimates in a school-based survey of Caucasian children 5-15 years of age report a prevalence of 2%.3
Although CVS is clearly misdiagnosed, in our experience this figure appears to be excessive, perhaps because the study was based on a questionnaire that did not involve exclusionary testing and because milder cases that did not require medical intervention were detected. In any case, in our reported pediatric gastroenterology experience, CVS was second only to gastroesophageal reflux disease as a cause of recurrent vomiting.4
