Cyclic vomiting syndrome

Cyclic vomiting syndrome
Classification and external resources
ICD-9	536.2
OMIM	500007
DiseasesDB	34706

Cyclic vomiting syndrome (US English) or cyclical vomiting syndrome (UK English) (CVS) is a condition whose symptoms are recurring attacks of intense nausea, vomiting and sometimes abdominal pain and/or headaches or migraines. Cyclic vomiting usually develops during childhood usually ages 3–7; although it often remits during adolescence, it can persist into adult life.^[1][2][3]

Patient characteristics

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.^[4] Typical delay in diagnosis from onset of symptoms is 2.7 – 3 years.^[4] Females show a slight predominance over males; the female-to-male ratio is 57:43.^[5] CVS occurs in all races but seems to disproportionately affect caucasians.

Genetics

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. ^[6] Charles Darwin's adult illnesses have been suggested to be due to this syndrome.^[7]

Background

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 into months, with a median episode duration of 41 hours.^[8] 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 emeses. Between episodes the sufferer is usually otherwise normal and healthy but can be in a weak state of fatigue or have muscle pain. In approximately half of sufferers 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 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 sometimes heightened sensitivity to especially light but also smell, sound, pressure, and temperature with sometimes oncoming muscle pain and fatigue is reported by some patients. The majority of sufferers, but not all, 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.

During an attack a sufferer may be light sensitive (photophobic), sound sensitive (phonophobic), and, less frequently, temperature or pressure sensitive.^[1] Some sufferers also have a strong urge to bathe in warm or cold water. Some sufferers reports 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 caused by dehydration rather than any underlying cause for the CVS.

Diagnostic criteria and investigations

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 diagnosis of CVS; essential criteria are:

1. A history of three or more periods of intense, acute nausea, and unremitting vomiting and sometimes pain lasting hours to days and even into months are reported.
2. Intervening symptom-free intervals, lasting weeks to months
3. Exclusion of metabolic, gastrointestinal or central nervous system structural or biochemical disease e.g. individuals with specific physical causes (e.g. intestinal malrotation)

During episodes of vomiting, blood sugar, fluid-electrolyte balance, and acid-base balance are monitored. Once formal investigations to rule out gastrointestinal or other etiologies have been conducted, these need not be repeated in future episodes.^[1]

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 to underdiagnosis, and thus the true figure may be higher.

Treatment

There is no known cure for CVS, but there are medications that can be used to treat, intervene in, and prevent attacks. There is a growing body of publications on either individual cases or experiences of cohorts of CVS patients. 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. Abortive therapy has limited success, but for a number of patients potent anti-emetic drugs such as ondansetron (Zofran) or granisetron (Kytril), dronabinol (Marinol), and more recently dextromethorphan may be helpful in either preventing an attack, aborting an attack or reducing the severity of an attack. In some instances, sedatives or painkillers (particularly morphine based) can be helpful.^{[citation needed]} Lifestyle changes may also be recommended, such as extended rest and/or reduction of stress.^{[citation needed]}

Course and outcome

Fitzpatrick et al. (2007) identified 41 children with cyclic vomiting. 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%).^{[citation needed]}

Most children who have this disorder miss on average 24 school days a year.^[9] The frequency of episodes is higher, for some people, during times of excitement.^[9] Charitable organizations to support sufferers and their families and to promote knowledge of CVS exist in several countries.

Mortality

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 salt imbalances and extremely high blood pressure often develops during an attack. The patient can also become undernourished or underfed if the attacks last too long. In underdeveloped countries it remains probable that CVS may contribute to mortality. In the developed world with adequate medical interventions most sufferers can be supported during an attack and will recover from the episode.^{[citation needed]}

Notes and references

1. ^ ^{a b c} Lindley KJ, Andrews PL. "Pathogenesis and Treatment of Cylical Vomiting." J Pediatric Gastroenterology and Nutrition 41 S38-S40 2005.
2. ^ Li BU et al., "North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Consensus Statement on the Diagnosis and Management of Cyclic Vomiting Syndrome". J Pediatric Gastroenterology and Nutrition 47 379-393 2008. Represents the official recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition for the diagnosis and management of Cyclic Vomiting Syndrome.
3. ^ Abell et al., 2008.
4. ^ ^{a b} Li and Misiewicz, 2003
5. ^ Li and Kagalwalla, 2002
6. ^ "What is cyclic vomiting syndrome?". http://ghr.nlm.nih.gov/condition/cyclic-vomiting-syndrome. 
7. ^ John A Hayman (2009). "Darwin's illness revisited". BMJ 339: b4968. doi:10.1136/bmj.b4968. PMID 20008377. http://www.bmj.com/content/339/bmj.b4968.full. 
8. ^ Li BU, Fleisher DR. "Cyclic vomiting syndrome: features to be explained by a pathophysiologic model." Dig Dis Sci 44: 13S–8S 1999.
9. ^ ^{a b} Li, BU; Li BUK, LeFevre F, Chelimsky GG, Boles RG, Nelson SP, Lewis DW, Linder SL, Issenman RM, Rudolph CD (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): 379–393. doi:10.1097/MPG.0b013e318173ed39. PMID 18728540. http://www.cvsaonline.org/pdfs/adams1-1.pdf. Retrieved 21 March 2011. 

• Abu-Arafeh I. & Russell G. "Cyclical vomiting syndrome in children: A population based study." Journal of Pediatric Gastroenterology and Nutrition, 21(4), 454-8 1995.
• Fleisher DR. "The cyclic vomiting syndrome described." J Pediatr Gastroenterol Nutr 21(Suppl. 1):S1–5 1995.
• Fleisher DR. "Empiric guidelines for the management of cyclical vomiting syndrome."
• Rasquin-Weber A, Hyman PE, Cucchiara S, et al. "Childhood functional gastrointestinal disorders." Gut 45 (Suppl. 2):II60–II8 1999.

External links

• Cyclic Vomiting Syndrome article
• The UK Cyclical Vomiting Syndrome Association
• The USA/Canadian CVS association
• The Italian CVS Society
• Spanish Cyclical Vomiting Syndrome 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