History of hot showers and recurrent vomiting? Consider cannabis

The patient presents with complaints of abdominal pain and cyclic bouts of nausea and vomiting. The only thing that provides relief, he says, is a hot shower. What’s his diagnosis? It’s not pregnancy, obviously. Is it cyclical vomiting syndrome? Gastroparesis? Intestinal obstruction? Pancreatobiliary disease?

Before you order a battery of tests or prescribe antiemetics, ask the patient if he smokes marijuana. With this history, chances are that the patient’s condition is cannabinoid hyperemesis syndrome (CHS).

Cannabinoid hyperemesis is a relatively newly recognized syndrome associated with heavy use of cannabis. Its defining symptoms include significant nausea, vomiting, and abdominal pain in the setting of chronic cannabis use. An essential tipoff to the diagnosis: Taking hot showers or baths to relive symptoms, according to a treatment guideline recently published in Western Journal of Emergency Medicine.

The guideline lists these diagnostic features:

• Cyclic nausea and vomiting
• Abdominal pain
• Regular (often heavy and at least weekly) cannabis use
• Hot showers for symptom relief
• Male predominance
• Resolution of symptoms after stopping cannabis

If the patient denies using cannabis but your suspicion remains high, consider a urine drug screen, the authors advised. Also, document “cannabis” or “marijuana” as part of the diagnosis in the medical record, as these patients frequently return for emergency care.

CHS is poorly recognized

Because marijuana is usually associated with relieving nausea in patients, clinicians don’t think to suspect it as a cause of nausea, the guideline authors noted. But with more states legalizing marijuana, the prevalence of CHS is increasing significantly. A 2015 study in Colorado found that after the state legalized cannabis, emergency visits for cyclic vomiting (which included CHS in the study) had nearly doubled.

“Despite the syndrome’s increasing prevalence, many physicians are unfamiliar with its diagnosis and treatment,” wrote the guideline’s authors, an expert panel of emergency medicine physicians from San Diego, CA. “Patients often present to the emergency department (ED) repeatedly and undergo extensive evaluations including laboratory examination, advanced imaging, and in some cases unnecessary procedures. They are exposed to an array of pharmacologic interventions including opioids that not only lack evidence, but may also be harmful.”

CHS treatment

Episodes typically last 1 to 2 days, but may last a week to 10 days. Treatment focuses on relieving symptoms and educating the patient about the need to stop using cannabis.

“Clinicians should inform patients that their symptoms are directly related to continued use of cannabis,” the authors stated. “They should further advise patients that immediate cessation of cannabis use is the only method that has been shown to completely resolve symptoms.”

Antipsychotics, such as haloperidol or olanzapine, have been reported to provide complete symptom relief. Antiemetics, including antihistamines, serotonin antagonists, dopamine antagonists, and benzodiazepines, have shown mixed results. Intravenous fluids and electrolyte replacement should be provided as needed. “Avoid opioids if the diagnosis of CHS is certain,” the authors advised.

Feel the heat

The pathophysiology of CHS is not well understood, they noted. The current hypothesis is that excessive cannabis use desensitizes or downregulates cannabinoid receptors, which dysregulates the endogenous cannabinoid system. “Some investigators have postulated that disruption of peripheral cannabinoid receptors in the enteric nerves may slow gastric motility, precipitating hyperemesis,” the authors wrote.

This is where hot showers fit in. “Relief of CHS symptoms with very hot water has highlighted a peripheral tissue receptor called TRPV₁, a G-protein coupled receptor that has been shown to interact with the endocannabinoid system, but is also the only known capsaicin receptor,” the guideline authors explained.

This fact led some ED physicians to use topical capsaicin cream to manage CHS symptoms. A randomized clinical trial of topical capsaicin cream for treating cyclic vomiting syndromes is now underway.