Cyclic Vomiting Syndrome (CVS) is characterized by episodes or cycles of severe nausea and vomiting that last for hours, or even days, that alternate with intervals with no symptoms.
Although originally thought to be a pediatric disease, CVS occurs in all age groups. In children CVS starts most often between the ages of 3 and 7.
Each episode of CVS is similar to previous ones, meaning the episodes tend to start at the same time of day, last the same length of time, and occur with the same symptoms and level of intensity. Episodes can be so severe that a person has to stay in bed for days, unable to go to school or work.
CVS has four phases:
- Symptom-free interval phase. This phase is the period between episodes when no symptoms are present.
- Prodrome phase. This phase signals that an episode of nausea and vomiting is about to begin. Often marked by nausea—with or without abdominal pain—this phase can last from just a few minutes to several hours. Sometimes, taking medicine early in the phase can stop an episode in progress. However, sometimes there is no warning; a person may simply wake up in the morning and begin vomiting.
- Vomiting phase. This phase consists of nausea and vomiting; an inability to eat, drink, or take medicines without vomiting; paleness; drowsiness; and exhaustion.
- Recovery phase. This phase begins when the nausea and vomiting stop. Healthy color, appetite, and energy return.
Many people can identify a specific condition or event that triggered an episode, such as an infection. Common triggers include:
- Emotional stress and excitement (in children)
- Anxiety and panic attacks
- Sinus problems
- The flu
- Eating certain foods such as chocolate or cheese
- Eating too much
- Eating just before going to bed
- Hot weather
- Physical exhaustion
- Motion sickness
A person who experiences the following symptoms for at least 3 months—with first onset at least 6 months prior—may have CVS:
- Vomiting episodes that start with severe vomiting—several times per hour—and last less than 1 week
- Three or more separate episodes of vomiting in the past year
- Absence of nausea or vomiting between episodes
A person with CVS may experience:
- Abdominal pain
- Sensitivity to light during vomiting episodes
Continued vomiting may cause severe dehydration that can be life threatening. Symptoms of dehydration include thirst, decreased urination, paleness, exhaustion, and listlessness. A person with any symptoms of dehydration should see a health care provider immediately.
The relationship between migraine and CVS is still unclear, but medical researchers believe the two are related.
The severe vomiting that defines CVS is a risk factor for several complications:
- Dehydration. Vomiting causes the body to lose water quickly. Dehydration can be severe and should be treated immediately.
- Electrolyte imbalance. Vomiting causes the body to lose important salts it needs to keep working properly.
- Peptic esophagitis. The esophagus—the tube that connects the mouth to the stomach—becomes injured from stomach acid moving through it while vomiting.
- Hematemesis. The esophagus becomes irritated and bleeds, so blood mixes with vomit.
- Mallory-Weiss tear. The lower end of the esophagus may tear open or the stomach may bruise from vomiting or retching.
- Tooth decay. The acid in vomit can hurt teeth by corroding tooth enamel.
CVS is hard to diagnose because no tests—such as a blood test or x ray—can establish a diagnosis of CVS.
Treatment varies, but people with CVS generally improve after learning to control their symptoms. People with CVS are advised to get plenty of rest and sleep and to take medications that prevent a vomiting episode, stop one in progress, speed up recovery, or relieve associated symptoms.
Once a vomiting episode begins, treatment usually requires the person to stay in bed and sleep in a dark, quiet room. Severe nausea and vomiting may require hospitalization and intravenous fluids to prevent dehydration. Sedatives may help if the nausea continues.
Sometimes, during the prodrome phase, it is possible to stop an episode from happening. For example, people with nausea or abdominal pain before an episode can ask their doctor about taking ondansetron (Zofran) or lorazepam (Ativan) for nausea or ibuprofen (Advil, Motrin) for pain. Other medications that may be helpful are ranitidine (Zantac) or omeprazole (Prilosec), which help calm the stomach by lowering the amount of acid it makes.
People whose episodes are frequent and long-lasting may be treated during the symptom-free intervals in an effort to prevent or ease future episodes. Medications that help people with migraine headaches are sometimes used during this phase, but they do not work for everyone. Taking the medicine daily for 1 to 2 months may be necessary before one can tell if it helps.