Cannabinoid Hyperemesis Syndrome (CHS): What Is It?

Cannabinoid Hyperemesis Syndrome (CHS) is a condition characterized by cyclic episodes of nausea, vomiting, and abdominal pain in individuals with a history of chronic cannabis use.  Despite being relatively rare, CHS has gained increasing recognition in the medical community due to the rising prevalence of cannabis use globally.

Below, we take a closer look at CHS and discuss how to not only identify but manage the resulting symptoms.

Rise to Prevalence

The first descriptions of CHS emerged in the early 2000s when a case series published by Allen et al. detailed patients with chronic cannabis use who experienced severe cyclic vomiting and found symptomatic relief through hot showers or baths.

This unique behavior, along with the resolution of symptoms upon cessation of cannabis use, helped distinguish CHS from other gastrointestinal disorders.

Pathophysiology

To this day, the exact pathophysiological mechanisms underlying CHS are poorly understood.  While this may be the case, there remain several hypotheses that could explain what is actually happening in those who suffer from the condition.

1. Cannabinoid Receptor Dysregulation: Chronic cannabis use may lead to dysregulation of the endocannabinoid system.  Cannabinoids exert their effects through CB1 and CB2 receptors.  Overstimulation of CB1 receptors in the brain and gastrointestinal tract may lead to altered gastrointestinal motility and hyperemesis.
2. Cannabinoid Toxicity: Prolonged exposure to high levels of cannabinoids might result in toxic effects on the gastrointestinal system, contributing to the cyclic vomiting observed in CHS.
3. Thermoregulatory Dysfunction: The relief of symptoms with hot showers or baths suggests a possible role of thermoregulatory dysfunction.  Cannabinoids are known to affect the hypothalamus, which regulates body temperature, and chronic use might disrupt normal thermoregulatory processes.

As it stands, the answer could be one of, all of, or even none of these explanations.  However, with our understanding of cannabis and its effect on the human body increasing due to less restrictive regulations, it is only a matter of time before a definitive answer is found.

Clinical Presentation

So, we’ve established with CHS was first documented, and how it may affect the human body behind-the-scenes.  How does one actually determine if they are presenting with symptoms associated with the condition, though?

CHS typically presents in three distinct phases:

1. Prodromal Phase: This phase can last for months to years and is characterized by early morning nausea, fear of vomiting, and abdominal discomfort.  Patients continue to use cannabis during this phase, often to relieve these symptoms, which paradoxically exacerbates the condition.
2. Hyperemetic Phase: This is the most debilitating phase, marked by intense and persistent nausea, vomiting, and abdominal pain. Patients may vomit several times per hour and experience weight loss, dehydration, and electrolyte imbalances. The compulsive hot bathing behavior, used to alleviate symptoms, is a hallmark of this phase.  Notably, patients relying on hot baths to alleviate symptoms may have a skewed perception of heat and unknowingly scald themselves as they require increasingly hot temperatures for this method to continue working.
3. Recovery Phase: Upon cessation of cannabis use, patients enter the recovery phase. Symptoms gradually resolve, usually within days to weeks. If cannabis use is resumed, the cycle often repeats.

This is a particularly difficult condition to overcome because, as noted, the cause of the symptoms also provides relief from them.  Those without the willpower or cognizance to push through a recovery phase may incorrectly believe that cannabis is actually the solution and not the cause.

Diagnosis

The diagnosis of CHS is primarily clinical, based on the patient’s history and presentation of both signs and symptoms.  Criteria that medical professionals typically look for when diagnosising CHS include:

• A history of chronic cannabis use
• Cyclic episodes of nausea and vomiting
• Relief of symptoms with hot showers or baths
• Resolution of symptoms after cessation of cannabis use

Another critical approach is the use of differential diagnosis.  To effectively deem a condition CHS, this means first ruling out other conditions that could present in a similar fashion.  This can be done through laboratory tests, imaging, endoscopy, and a thorough examination of the patient’s body, history, and presentation.  For CHS in particular, it is key to rule out other conditions related to cyclic vomiting, such as gastrointestinal obstructions, metabolic disorders, and infections.

Management

The management of CHS involves both acute treatment during the hyperemetic (vomiting) phase and long-term strategies to prevent recurrence:

1. Acute Management:
   • Hydration and Electrolyte Replacement: Intravenous fluids and electrolyte replacement are crucial to address dehydration and electrolyte imbalances.
   • Antiemetic Medications: Traditional antiemetics, such as metoclopramide, may be used, though their efficacy can vary in CHS.
   • Capsaicin Cream: The topical application of capsaicin cream to the abdomen has shown some efficacy, possibly by desensitizing TRPV1 receptors involved in pain and nausea.
2. Long-Term Management:
   • Cessation of Cannabis Use: The cornerstone of long-term management is the complete cessation of cannabis use. Counseling and support groups may be beneficial for patients struggling with cessation/addiction.
   • Patient Education: Educating patients about the relationship between cannabis use and their symptoms is essential to prevent relapse.
   • Follow-Up Care: Regular follow-up visits to monitor for recurrence of symptoms and support abstinence from cannabis are important.

Conclusion

Cannabinoid Hyperemesis Syndrome is a challenging condition that requires increased awareness and understanding among not just healthcare professionals, but those that find themselves regular cannabis users.  Recognition of the syndrome, coupled with appropriate management strategies, can significantly improve patient outcomes.

Simply put – as cannabis use continues to rise, especially with increasing legalization, the importance of education and research on CHS becomes more critical than ever.