What causes CVS?

No one knows for sure what causes CVS. It’s likely related to migraine headaches, with similar triggers. Sometimes, if a family member suffers migraines, children might be more likely to have CVS. It can affect children of any age. Most often, it first shows up in children from ages 3 to 7. Children with CVS may also have other GI (gastrointestinal) issues or health problems.

What can trigger a CVS episode?

Different things can trigger an episode. The most common triggers include:

• Stress or excitement (such as holidays, school events, or vacations)

• Viral infections (such as colds)

• Allergies or sinus problems

• Foods (such as chocolate or cheese)

• Motion sickness

• Menstrual period

• Lack of sleep

• Exhaustion

The 4 phases of CVS

CVS happens in four phases or stages:

• Prodrome phase. This phase signals that an episode is about to start. Symptoms include: aura (odd sensations), sensitivity to light, stomach pain, headache, or nausea. The prodrome phase can come on in minutes, or it can come on over a few hours. An episode can sometimes be stopped during this phase with medicine.

• Episode phase. During this phase, your child has vomiting, retching, and nausea. It can last for many hours or even days. Your child may not be able to take any food or medicines by mouth.

• Recovery phase. This phase starts when vomiting or retching stops. Your child is likely exhausted. She or he may fall asleep right away. It's common for children to wake up with muscle pain from the vomiting.

• Symptom-free phase. The symptom-free phase is the time when your child feels fine. It may last weeks or months before another episode.

How is CVS diagnosed?

To diagnose CVS, the healthcare provider must first rule out other problems. The healthcare provider will ask about your child’s health history. This can help show the cycle of symptoms that point toward CVS. Tests may also be done, including blood tests to rule out other causes of vomiting. Radiology tests, such as an upper GI series, may also be done. This test can show the healthcare provider if there is a problem with your child's digestive system. 

How is CVS treated?

There is no cure for CVS. But you and your child can learn ways to try to prevent episodes. You can also learn how to stop an episode as it starts (see Preventing Future Episodes). Once severe vomiting starts, though, your child will likely need to go to the hospital right away. At the hospital, your child will get medicines to try to stop the vomiting. Your child will likely need fluids to stay hydrated. This is usually done using an intravenous (IV) line. If needed, nutrition can also be given to your child through the IV line. Your child will likely stay in the hospital until the episode stops. There, your child can also get care during the recovery phase.

Preventing future episodes

CVS episodes can be stressful and scary for you and for your child. It might help to know that you can act to prevent or manage episodes. Start by learning your child’s triggers. If your child is exposed to a trigger, or has prodrome symptoms, take action as directed by the healthcare provider. This can help stop the episode before it even starts. Sometimes, an episode can’t be prevented or stopped at home. When this happens, your child will need to be admitted to the hospital or emergency room. There, your child will get needed treatment, fluids, and observation. If your child has episodes often, longer term medicines may be effective at decreasing the frequency and severity of attacks. 

Long-term concerns

The good news is that children can outgrow CVS. This often happens in their teens. However, they may be more likely to have migraine headaches as adults. Your child may also be at higher risk for anxiety. For now, you should pay careful attention to your child’s teeth. Repeated vomiting can destroy tooth enamel due to the strong acids in your child’s stomach. This can lead to tooth decay. To help prevent tooth decay:

• Have your child rinse the mouth often with water during episodes.

• Make sure your child sees a dentist at least twice a year.

Call 911

Call 911 if your child has any of the following:

• Trouble breathing

• Confusion

• Very drowsy or trouble waking up

• Fainting or loss of consciousness

• Rapid heart rate

• Chest pain

When to call your child's healthcare provider

Call your child's healthcare provider right away if they have any of these:

• Fever (see Fever and children below)

• Unable to keep liquids down (continued vomiting) for 24 hours

• Less urine than usual or extreme thirst

• Pain that gets worse

• Symptoms that don’t get better, or get worse

• New symptoms

Fever and children

Use a digital thermometer to check your child’s temperature. Don’t use a mercury thermometer. There are different kinds and uses of digital thermometers. They include:

• Rectal. For children younger than 3 years, a rectal temperature is the most accurate.

• Forehead (temporal). This works for children age 3 months and older. If a child under 3 months old has signs of illness, this can be used for a first pass. The provider may want to confirm with a rectal temperature.

• Ear (tympanic). Ear temperatures are accurate after 6 months of age, but not before.

• Armpit (axillary). This is the least reliable but may be used for a first pass to check a child of any age with signs of illness. The provider may want to confirm with a rectal temperature.

• Mouth (oral). Don’t use a thermometer in your child’s mouth until they are at least 4 years old.

Use the rectal thermometer with care. Follow the product maker’s directions for correct use. Insert it gently. Label it and make sure it’s not used in the mouth. It may pass on germs from the stool. If you don’t feel OK using a rectal thermometer, ask the healthcare provider what type to use instead. When you talk with any healthcare provider about your child’s fever, tell them which type you used.

Below are guidelines to know if your young child has a fever. Your child’s healthcare provider may give you different numbers for your child. Follow your provider’s specific instructions.

Fever readings for a baby under 3 months old:

• First, ask your child’s healthcare provider how you should take the temperature.

• Rectal or forehead: 100.4°F (38°C) or higher

• Armpit: 99°F (37.2°C) or higher

Fever readings for a child age 3 months to 36 months (3 years):

• Rectal, forehead, or ear: 102°F (38.9°C) or higher

• Armpit: 101°F (38.3°C) or higher

Call the healthcare provider in these cases:

• Repeated temperature of 104°F (40°C) or higher in a child of any age

• Fever of 100.4° (38°C) or higher in baby younger than 3 months

• Fever that lasts more than 24 hours in a child under age 2

• Fever that lasts for 3 days in a child age 2 or older