Overview
Definition:
Cyclic vomiting syndrome (CVS) is a functional gastrointestinal disorder characterized by recurrent, stereotypic episodes of intense nausea and vomiting separated by intervals of normal health
It is often associated with migraines, particularly in older children and adults.
Epidemiology:
CVS is estimated to affect 1-3% of school-aged children
It is more common in females
The onset is typically between 3 to 7 years of age
There is a strong association with a family history of migraines (up to 80% of affected children have a parental history).
Clinical Significance:
CVS can significantly impact a child's quality of life, leading to school absenteeism, parental anxiety, and substantial healthcare utilization
Early diagnosis and appropriate management are crucial to prevent complications and improve outcomes for affected children.
Clinical Presentation
Symptoms:
Stereotypic episodes of intense nausea
Forceful vomiting, often occurring multiple times per hour
Episodes typically last for several hours to several days
Severe abdominal pain, often diffuse or epigastric
Pallor
Lethargy
Anorexia during episodes
Episodes are usually similar in pattern, duration, and intensity.
Signs:
During an episode: Signs of dehydration (dry mucous membranes, decreased skin turgor, sunken eyes, reduced urine output)
Tachycardia
Hypotension may occur in severe dehydration
Abdominal tenderness, usually diffuse, without localized signs of peritonitis
Normal examination between episodes.
Diagnostic Criteria:
Rome IV Criteria for Cyclic Vomiting Syndrome: At least 5 episodes meeting criteria A-D within a 6-month period
A: Stereotypic and recurrent episodes of intense nausea and vomiting lasting hours to days
B: Vomiting occurs at least 4 times per hour or 3 times per 24 hours during an episode
C: Each episode is followed by complete return to usual health lasting weeks to months
D: Episodes are not better accounted for by another disorder.
Diagnostic Approach
History Taking:
Detailed history of the vomiting episodes: onset, duration, frequency, intensity, associated symptoms (pain, pallor, lethargy)
Timing of episodes relative to meals, sleep, stress
Associated symptoms like headache, photophobia, phonophobia
Family history of migraines or CVS
Diet and recent food intake
Medications
Rule out red flags: fever, diarrhea, bloody stools, focal neurological signs, abdominal distension with absent bowel sounds (suggesting obstruction).
Physical Examination:
Perform a thorough physical examination, focusing on hydration status, vital signs, and abdominal examination
Look for signs of dehydration
Assess for abdominal tenderness, guarding, or masses
Evaluate for neurological deficits
Examine ears, nose, and throat for other potential causes of vomiting
Perform a complete systemic examination.
Investigations:
Investigations are primarily to rule out organic causes of vomiting
Basic metabolic panel (BMP) to assess electrolytes and hydration status, especially for sodium, potassium, chloride, bicarbonate, BUN, and creatinine
Complete blood count (CBC) to rule out infection
Urinalysis for ketones and specific gravity
Liver function tests (LFTs)
Amylase and lipase if pancreatitis is suspected
Abdominal ultrasound to rule out structural abnormalities, appendicitis, or cholecystitis
Upper endoscopy or barium studies may be considered in select cases if obstruction or structural anomalies are suspected
EEG if seizures are a concern
Brain MRI if neurological causes are suspected.
Differential Diagnosis:
Other causes of recurrent vomiting in children including: Gastroparesis, intestinal obstruction (e.g., intussusception, adhesions, volvulus), peptic ulcer disease, gastroesophageal reflux disease (GERD), food allergies/intolerances, metabolic disorders (e.g., inborn errors of metabolism), CNS disorders (e.g., increased intracranial pressure, tumors, epilepsy), cyclic neutropenia, migraines with abdominal aura, poisoning, infections (e.g., UTI, meningitis).
Prophylaxis And Management
Trigger Identification And Avoidance:
Identify and avoid common triggers: Stress (school, family conflicts)
Lack of sleep
Excitement or anticipation
Certain foods (chocolate, cheese, monosodium glutamate, caffeine, processed meats)
Illness
Menstruation (in adolescents).
Pharmacological Prophylaxis:
Initiate prophylactic medications, especially if episodes are frequent or debilitating
Medications are typically given daily
Options include: Tricyclic antidepressants (e.g., Amitriptyline 0.25-1 mg/kg/day divided BID/TID
maximum dose 1 mg/kg/day or 25-50 mg/day)
Beta-blockers (e.g., Propranolol 1-3 mg/kg/day divided BID/TID
maximum dose 40 mg/day)
Anticonvulsants (e.g., Topiramate 1-2 mg/kg/day divided BID
monitor for side effects
doses up to 3 mg/kg/day may be needed)
Cyproheptadine (an antihistamine with potential antimigraine effects) 0.25 mg/kg/day divided BID/TID
maximum dose 12 mg/day
Coenzyme Q10 and L-carnitine have also shown promise in some studies.
Acute Episode Management:
During an acute episode, focus on supportive care and symptom relief
Hydration is paramount: Oral rehydration solution (ORS) if tolerated, otherwise intravenous fluids
Medications for nausea and vomiting: Ondansetron (0.1 mg/kg IV/PO every 8 hours or as needed, maximum 4 mg per dose for children under 12) is often the first choice
Other antiemetics like domperidone can be used if available and appropriate
Sedation for comfort: Benzodiazepines (e.g., lorazepam 0.05 mg/kg IV/PO) can help with anxiety and reduce vomiting, but should be used cautiously
Triptans (e.g., Sumatriptan) may be considered in older children and adolescents if migraine is strongly suspected and other treatments fail, but evidence in CVS is limited.
Lifestyle Modifications:
Encourage regular sleep patterns
Stress management techniques such as relaxation exercises or counseling
Regular meals and avoidance of skipping meals
Maintain a food diary to identify potential dietary triggers.
Complications
Early Complications:
Dehydration leading to electrolyte imbalances (hypokalemia, hypochloremia, metabolic alkalosis)
Esophagitis and Mallory-Weiss tears from forceful vomiting
Esophageal rupture (rare)
Aspiration pneumonia.
Late Complications:
Failure to thrive or poor growth due to chronic malnutrition
Dental enamel erosion from frequent vomiting
Social and academic impairment due to frequent school absences
Development of chronic abdominal pain
Increased risk of psychiatric comorbidities like anxiety and depression.
Prevention Strategies:
Strict adherence to prophylactic medication regimens
Diligent identification and avoidance of known triggers
Education of child and family on trigger avoidance and management strategies
Regular follow-up with a pediatric gastroenterologist to adjust treatment as needed.
Prognosis
Factors Affecting Prognosis:
Early diagnosis and initiation of prophylactic treatment
Effective trigger avoidance
Family history of migraines may indicate a better response to antimigraine-based prophylaxis
Co-occurrence of migraine headaches.
Outcomes:
With appropriate prophylactic treatment and trigger avoidance, many children experience a significant reduction in the frequency and severity of episodes
Some children may outgrow CVS by adolescence
However, a subset of patients may have persistent symptoms into adulthood.
Follow Up:
Regular follow-up appointments with a pediatric gastroenterologist are essential, typically every 3-6 months, to monitor treatment response, assess adherence, adjust medications, and address any emerging complications or psychosocial issues
Transition to adult care should be planned as the child approaches adolescence.
Key Points
Exam Focus:
Rome IV criteria for CVS
Stereotypy of episodes (pattern, duration, intensity)
Association with migraine
Importance of ruling out organic causes with investigations
Prophylactic medications: Amitriptyline, Propranolol, Topiramate
Acute management: hydration and antiemetics (Ondansetron).
Clinical Pearls:
Always ask about family history of migraines
The history is key
often investigations are normal between episodes
Educate parents thoroughly on trigger avoidance and medication adherence
Consider co-analgesics or triptans in adolescents with migraine-like features
Be patient
finding the right prophylactic regimen can take time.
Common Mistakes:
Misdiagnosing CVS as functional abdominal pain or gastroenteritis, leading to delayed treatment
Failing to adequately investigate for organic causes
Inconsistent adherence to prophylactic medications
Underestimating the impact of stress and sleep on episode frequency.