Approach to a Child with Cyclic Vomiting Syndrome

Cyclic vomiting syndrome (CVS) is a rare disorder characterized by recurrent episodes of severe nausea and vomiting. An episode may last for a few hours to several days and then is followed by a period of time during which affected individuals are free of severe nausea and vomiting. This alternating pattern of disease and disease-free periods distinguishes cyclic vomiting syndrome from other similar disorders.

Etiology

Cyclic vomiting syndrome (CVS) is a chronic functional disorder of unknown etiology that is characterized by paroxysmal, recurrent episodes of vomiting. The pathophysiology is unknown, but data suggest a strong genetic component.

Cyclic vomiting usually develops during childhood usually ages 3–7; although it often remits during adolescence, it can persist into adult life.

Epidemiology
Cyclic vomiting syndrome occurs in all races but seems to disproportionately affect whites.
Females show a slight predominance over males.

Causes and Risk Factors
The cause of cyclic vomiting syndrome is unknown, but the bouts of vomiting that characterize the condition can be triggered by:

• Colds, allergies or sinus problems
• Emotional stress or excitement
• Foods such as chocolate or cheese
• Overeating or eating right before going to bed
• Hot weather
• Physical exhaustion

Many children who have cyclic vomiting syndrome have a family history of migraines or begin having migraines themselves when they get older. 

Abdominal migraine — a type of migraine more common in children — causes abdominal pain but not the severe vomiting associated with cyclic vomiting syndrome.

Four Phases Of CVS
CVS has four phases:

1. Symptom-free interval phase. This phase is the period between episodes when no symptoms are present.
2. 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.
3. Vomiting phase. This phase consists of nausea and vomiting; an inability to eat, drink, or take medicines without vomiting; paleness; drowsiness; and exhaustion.
4. Recovery phase. This phase begins when the nausea and vomiting stop. Healthy color, appetite, and energy return.

Clinical Signs and Symptoms
Cyclic vomiting syndrome causes:

• Severe vomiting
• Nausea
• Loss of appetite
• Gagging
• Pale complexion, often appears before a vomiting episode
• Extreme fatigue

These signs and symptoms may occur an average of six times an hour. Episodes in children generally last only a day or two. Episodes typically begin late at night or early in the morning.

In addition, some people with cyclic vomiting syndrome may develop:
Sensitivity to light

• Headache
• Fever
• Dizziness
• Diarrhea
• Abdominal pain

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:

• 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.
• 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 (e.g. intestinal malrotation)

Once formal investigations to rule out gastrointestinal or other etiologies have been conducted, these need not be repeated in future episodes.

Management
In the absence of known pathophysiology, treatment of cyclic vomiting syndrome (CVS) remains empiric. The following management strategies are used for cyclic vomiting syndrome:

• avoidance of triggers,
• prophylactic and abortive therapy,
• supportive care during acute episodes, and
• family support.

There’s no cure for cyclic vomiting syndrome. To control the signs and symptoms, the child may need:

• Anti-nausea drugs
• Sedatives
• Acid-suppressing medications
• Hospitalization for intravenous fluids to prevent dehydration

In many cases, the same types of medications used for migraines often help stop or even prevent episodes of cyclic vomiting. These medications include:

• Tricyclic antidepressants, such as amitriptyline and nortriptyline
• Triptans, such as sumatriptan and zolmitriptan
• Analgesics, such as ibuprofen