Cyclic vomiting syndrome
|Cyclic vomiting syndrome|
|Classification and external resources|
Cyclic vomiting syndrome (US English) or cyclical vomiting syndrome (UK English) (CVS) is a chronic functional condition of unknown aetiology characterised by recurring attacks of intense nausea, vomiting and sometimes abdominal pain, headaches or migraines. CVS typically develops during childhood, usually between ages 3 and 7; although it often remits during adolescence, it can persist into adult life.
The average age at onset is 3–7 years, but CVS has been seen in infants who are as young as 6 days and in adults who are as old as 73 years. Typical delay in diagnosis from onset of symptoms is 2.7 – 3 years. Females show a slight predominance over males; the female-to-male ratio is 57:43. CVS occurs in all races but seems to disproportionately affect Caucasians.
Sufferers may vomit or retch six to twelve times an hour, and an episode may last from a few hours to well over three weeks, and in some cases months, with a median episode duration of 41 hours. Acid, bile and (if the vomiting is severe) blood may be vomited. Some sufferers will ingest water to reduce the irritation of bile and acid on the esophagus during emesis. Between episodes the sufferer is usually normal and healthy otherwise but can be in a weak state of fatigue or suffer from muscle pain. In approximately half of cases the attacks, or episodes, occur in a time-related manner. Each attack is stereotypical: that is, in any given individual, the timing, frequency and severity of attacks is similar.
Episodes may happen every few days, every few weeks or every few months. For some there is not a pattern in time that can be recognized. Some sufferers have a warning of an attack: They may experience a prodrome, usually intense nausea and pallor, heightened sensitivity, especially to light, though sensitivity to smell, sound, pressure, and temperature, as well as oncoming muscle pain and fatigue, are also reported by some patients. The majority of sufferers can identify triggers that may precipitate an attack. The most common are various foods, infections (such as colds), menstruation, extreme physical exertion, lack of sleep, and psychological stresses both positive and negative.
A sufferer may also be light-sensitive (photophobic) during an attack, as well as sound-sensitive (phonophobic) and, less frequently, temperature- or pressure-sensitive. Some sufferers also have a strong urge to bathe in warm or cold water. Some sufferers report that they experience a restless sensation or stinging pain along the spine, hands, and feet followed by weakness in both legs. Some of these symptoms may be due to dehydration rather than the underlying cause of CVS.
The cause of CVS has not been determined; there are no diagnostic tests for CVS. Several other medical conditions can mimic the same symptoms, and it is important to rule these out. If all other possible causes have been excluded, a diagnosis of CVS may be appropriate.
There are established criteria to aid in diagnosis of CVS; essential criteria are:
- A history of three or more periods of intense, acute nausea and unremitting vomiting, as well as pain in some cases, lasting hours to days and even weeks or months
- Intervening symptom-free intervals, lasting weeks to months
- Exclusion of metabolic, gastrointestinal, or central nervous system structural or biochemical disease, e.g., individuals with specific physical causes (such as intestinal malrotation)
Once formal investigations to rule out gastrointestinal or other etiologies have been conducted, these tests do not need to be repeated in the event of future episodes.
There is no known cure for CVS, but there are medications that can be used for treatment, intervention, and prevention. There is a growing body of publications on both individual cases and the experiences of the CVS cohort. Treatment is usually on an individual basis, based on trial and error.
The most common therapeutic strategies for those already in an attack are maintenance of salt balance by appropriate intravenous fluids and, in some cases, sedation. Having vomited for a long period prior to attending a hospital, patients are typically severely dehydrated. For a number of patients, potent anti-emetic drugs such as ondansetron (Zofran) or granisetron (Kytril), and dronabinol (Marinol) may be helpful in either preventing an attack, aborting an attack, or reducing the severity of an attack. Lifestyle changes may be recommended, such as extended rest and reduction of stress. Because the symptoms of CVS are similar (or perhaps identical) to those of the disease well-identified as "abdominal migraine," treatment of CVS with a regimen of anti-migraine drugs, such as Topirimate and amitryptiline, is showing promise in preventing recurrent attacks.
Many affected individuals have a family history of related conditions, such as migraines, in their mothers and maternal relatives, suggesting mitochondrial inheritance. Single base-pair and DNA rearrangements in the mitochondrial DNA have been associated with these traits. 
Fitzpatrick et al. (2007) identified 41 children with CVS. The mean age of the sample was 6 years at the onset of the syndrome, 8 years at first diagnosis, and 13 years at follow-up. As many as 39% of the children had resolution of symptoms immediately or within weeks of the diagnosis. Vomiting had resolved at the time of follow-up in 61% of the sample. Many children, including those in the remitted group, continued to have somatic symptoms such as headaches (in 42%) and abdominal pain (in 37%).
Most children who have this disorder miss on average 24 school days a year. The frequency of episodes is higher for some people during times of excitement. Charitable organizations to support sufferers and their families and to promote knowledge of CVS exist in several countries.
There is little hard evidence of death as a result of the condition. However, in severe cases the fluid loss can lead to potentially life-threatening electrolyte imbalances. The patient can also become malnourished if the attacks last too long without adequate replenishment of nutrients. With adequate medical interventions, most patients can be properly supported during an episode.
The prevalence of the condition is not clear. Two published studies on childhood CVS suggest nearly 2% of school-age children may have CVS. However, diagnosis is problematic and, as knowledge of CVS has increased in recent years, more and more cases are emerging. This suggests a tendency toward under-diagnosis, and thus the true figure may be higher.
It was first described by paediatrician Samuel Gee in 1882. It has been suggested that Charles Darwin's adult illnesses may have been due to this syndrome.
- Lindley, Keith J; Andrews, Paul L (2005). "Pathogenesis and Treatment of Cyclical Vomiting". Journal of Pediatric Gastroenterology & Nutrition 41 (Suppl 1): S38–40. doi:10.1097/01.scs.0000180299.04731.cb. PMID 16131963.
- Li, B UK; Lefevre, Frank; Chelimsky, Gisela G; Boles, Richard G; Nelson, Susanne P; Lewis, Donald W; Linder, Steven L; Issenman, Robert M et al. (2008). "North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Consensus Statement on the Diagnosis and Management of Cyclic Vomiting Syndrome". Journal of Pediatric Gastroenterology and Nutrition 47 (3): 379–93. doi:10.1097/MPG.0b013e318173ed39. PMID 18728540.
- Abell, T. L.; Adams, K. A.; Boles, R. G.; Bousvaros, A.; Chong, S. K. F.; Fleisher, D. R.; Hasler, W. L.; Hyman, P. E. et al. (2008). "Cyclic vomiting syndrome in adults". Neurogastroenterology & Motility 20 (4): 269–84. doi:10.1111/j.1365-2982.2008.01113.x. PMID 18371009.
- Li, B U.K; Misiewicz, Larry (2003). "Cyclic vomiting syndrome: A brain–gut disorder". Gastroenterology Clinics of North America 32 (3): 997–1019. doi:10.1016/S0889-8553(03)00045-1. PMID 14562585.
- Li, BU; Fleisher, DR (1999). "Cyclic vomiting syndrome: Features to be explained by a pathophysiologic model". Digestive diseases and sciences 44 (8 Suppl): 13S–18S. PMID 10490033.
- "What is cyclic vomiting syndrome?".
- Fitzpatrick, E; Bourke B, Drumm B, Rowland M (2008 Apr). "The incidence of cyclic vomiting syndrome in children: population-based study". Am J Gastroenterol. 103 (4): 991–5. PMID 18070235.
- Hayman, J. A (2009). "Darwin's illness revisited". BMJ 339: b4968. doi:10.1136/bmj.b4968. PMID 20008377.
- Abu-Arafeh, Ishaq; Russell, George (1995). "Cyclical Vomiting Syndrome in Children". Journal of Pediatric Gastroenterology and Nutrition 21 (4): 454–8. doi:10.1097/00005176-199511000-00014. PMID 8583299.
- Fleisher, DR (1995). "The cyclic vomiting syndrome described". Journal of pediatric gastroenterology and nutrition 21 (Suppl 1): S1–5. PMID 8708859.
- Fleisher, David R. "Empiric Guidelines for the Management of Cyclic Vomiting Syndrome".
- Rasquin-Weber, A; Hyman, PE; Cucchiara, S; Fleisher, DR; Hyams, JS; Milla, PJ; Staiano, A (1999). "Childhood functional gastrointestinal disorders". Gut 45 (Suppl 2): II60–8. PMC 1766693. PMID 10457047.
- Cyclic Vomiting Syndrome Emedicine article
- The UK Cyclical Vomiting Syndrome Association
- The USA/Canadian CVS association
- CVS page at the US National Digestive Diseases Clearinghouse, NIH Publication No. 04-4548
- An article in the Washington Post describing how the syndrome can be confused for other things