The Rising Trend of Cannabis-Linked Vomiting Syndrome in the US
A rare and increasingly prevalent condition, cannabinoid hyperemesis syndrome (CHS), is causing concern among healthcare professionals in the United States. CHS is a severe and cyclical vomiting disorder associated with chronic cannabis use, marked by intense nausea, abdominal pain, and vomiting.
The first case of CHS in the US was reported in 2009, and until recently, it lacked a national diagnostic code, making it challenging to track. Emergency department visits are crucial for identifying affected individuals and understanding the underlying causes.
Between 2016 and 2022, researchers at the University of Illinois Chicago observed a significant increase in CHS cases, rising from 4 visits per 100,000 people to 22 visits per 100,000. This trend is concerning, especially considering the potential for symptom relief and the possibility of halting the condition through cannabis cessation.
While CHS is still considered rare, its increasing prevalence warrants attention. Frequent cannabis use, particularly among younger individuals, is associated with the development of CHS, but it's not an inevitable outcome. The syndrome typically progresses over the first few years after initial use, starting with morning nausea or abdominal pain, and can persist for years.
A critical stage occurs when patients experience overwhelming and recurrent vomiting and nausea for a day or two after cannabis use. Interestingly, a hot bath or shower can provide temporary relief from these symptoms. However, the most effective way to manage CHS is to stop using cannabis.
The COVID-19 pandemic played a significant role in the surge of CHS cases. During 2020-2021, researchers James Swartz and Dana Franceschini found a substantial increase in CHS prevalence in US emergency departments. Their study analyzed approximately 806 million ER visits nationwide and is the third national study to investigate CHS trends.
Hospital visits for CHS were most common among individuals aged around 30, with a slightly higher incidence in females. The condition was more prevalent in the West and Northeast compared to the South. The question remains whether the increase is due to more frequent cannabis use or improved awareness and diagnosis.
Swartz and Franceschini propose that the pandemic's stress, isolation, and increased cannabis use may have catalyzed the rise in CHS cases. However, other researchers argue that the higher percentage of diagnoses might be attributed to increased recognition of CHS and publication bias for a newly recognized syndrome.
Historically, CHS has been described as 'rare but relevant' and often misunderstood. In some cases, it takes up to 17 hospital admissions to receive a diagnosis, and patients may be accused of exaggerating their symptoms. Diagnosing CHS requires ruling out other possible explanations, and cannabis use is a crucial factor in the diagnostic process.
The absence of a clear rise in CHS cases before 2020, despite expanding cannabis legalization and high-potency products, presents a paradox. Swartz and Franceschini suggest that underdiagnosis or misclassification before 2020 may have contributed to the post-2020 surge, reflecting both increased exposure and heightened diagnostic vigilance.
Further research and better diagnostics are essential to determine the true rarity of CHS. The study was published in JAMA Network Open, shedding light on this critical issue and emphasizing the need for awareness and understanding in the medical community.
