CHS vs Cyclic Vomiting Syndrome: How to Tell the Difference

The Diagnostic Dilemma

Cannabinoid Hyperemesis Syndrome (CHS) and Cyclic Vomiting Syndrome (CVS) present with strikingly similar symptoms: episodes of severe nausea, intense vomiting, and abdominal pain that come and go in cycles. This overlap leads to frequent misdiagnosis, with CHS patients sometimes going years before receiving the correct diagnosis.

Key Differences

Cannabis Use History

The most critical differentiator is cannabis use. CHS occurs exclusively in people who use cannabis regularly, typically for months to years. CVS, by contrast, can affect anyone regardless of cannabis use.

CHS indicators:

• Heavy, regular cannabis use (usually daily or near-daily)
• Symptoms began after establishing a regular cannabis habit
• Symptoms resolve completely with sustained cessation of cannabis

CVS indicators:

• No cannabis use, or symptoms preceded cannabis use
• Symptoms persist regardless of cannabis use status
• Often has family history of migraines

Compulsive Hot Bathing

Perhaps the most distinctive feature of CHS is the compulsive need for hot showers or baths during episodes. Approximately 90% of CHS patients report that hot water provides significant temporary relief. While some CVS patients may find warm baths soothing, the compulsive, repeated bathing behavior is much more characteristic of CHS.

Response to Cannabis Cessation

This is the definitive test. CHS symptoms resolve completely after sustained cannabis cessation (typically within 1-2 weeks, though it can take longer). CVS symptoms do not respond to cannabis cessation.

Onset Pattern

CHS typically develops after years of cannabis use. The average duration of use before onset is 3-5 years, though it can occur sooner with heavy use. CVS often begins in childhood or adolescence and has no relationship to substance use.

Diagnostic Criteria (Rome IV)

The Rome IV criteria for CHS require all of the following:

1. Stereotypical episodic vomiting resembling CVS in onset, duration, and frequency
2. Presentation after prolonged, excessive cannabis use
3. Relief of vomiting episodes after sustained cessation of cannabis use

Why Does This Matter?

Correct diagnosis matters because the treatments are different. CHS is treated primarily by stopping cannabis use. CVS may be treated with tricyclic antidepressants, triptans, or other medications. Treating CHS as CVS means the patient continues using cannabis, perpetuating the cycle.

What To Do

If you're experiencing cyclic vomiting and use cannabis regularly:

1. Be honest with your doctor about your cannabis use
2. Consider a trial of cannabis cessation (at least 2-4 weeks)
3. Track your symptoms during the cessation period
4. Bring our ER Information Sheet to your doctor

If your symptoms resolve with cessation, CHS is the likely diagnosis. If they persist, further evaluation for CVS and other conditions is warranted.

References

• Venkatesan T, et al. "Cyclic Vomiting Syndrome and Cannabinoid Hyperemesis." Curr Treat Options Gastroenterol. 2019.
• Sorensen CJ, et al. "Cannabinoid Hyperemesis Syndrome: Diagnosis, Pathophysiology, and Treatment." J Med Toxicol. 2017.