Abstract
Distinguishing between cannabinoid hyperemesis syndrome and cyclic vomiting syndrome (CVS) in patients with cyclical vomiting and heavy cannabinoid use is a significant diagnostic challenge. A critical consideration is catamenial CVS, a subtype of CVS in which vomiting episodes are closely linked to the menstrual cycle. This pattern is frequently overlooked in cannabinoid users due to the overlapping symptomatology of both conditions. However, identifying a menstrual association with vomiting episodes is crucial for diagnosing catamenial CVS because hormonal contraceptive therapy is an effective treatment. We present 2 adolescent cases of cyclical vomiting with cannabis use, where further clinical investigation revealed the menstrual cycle as a key trigger for vomiting, ultimately leading to successful treatment with hormonal contraception despite continued cannabis use. Clinicians should always consider menstrual history in patients with cyclical vomiting to facilitate early and accurate diagnosis and timely treatment of catamenial CVS.
INTRODUCTION
Encountering cannabinoid use in patients with vomiting presents a challenging diagnostic scenario for clinicians. It often raises the question of whether they have cyclical vomiting syndrome (CVS) or cannabinoid hyperemesis syndrome (CHS). ROME IV criteria can diagnose both CVS and CHS. CVS criteria include stereotypical vomiting episodes of acute onset and absence of symptoms in between. CHS comprises of stereotypic vomiting episodes after prolonged cannabinoid use and symptom resolution after stopping cannabinoid use (Table 1).1 Hot showering, once a key feature of CHS, is now known to relieve symptoms in about 50% of patients with CVS.2 Distinguishing between these 2 diagnoses is crucial and poses a challenge for the clinician. Without a clear test to diagnose CHS, the best advice clinicians can offer their patients is unsatisfying: empiric cannabinoid abstinence for at least 3 vomiting cycles to differentiate CHS from CVS. This calls on the clinician to consider additional syndromes, such as catamenial CVS, with differentiating symptoms that when treated can lead to rapid clinical improvement.