Two case series and numerous individual case reports have been published on Cannabinoid Hyperemesis Syndrome (CHS) (). Patients present with recurrent episodes of nausea, vomiting, and dehydration with frequent visits to the emergency department. [6
]. Patients are typically young adults with a long history of cannabis use. In nearly all cases there is a delay of several years in the onset of symptoms preceded by chronic marijuana abuse [6
]. In one study the average duration of cannabis use prior to onset of recurrent vomiting was 16.3 ± 3.4 years [62
]. There are at least four reported cases where the time lag was equal to or less than three years [54
]. Daily marijuana use is characteristic and often reported as exceeding three to five times per day.
Epidemiology, clinical presentation and follow up of patients with Hyperemesis Cannabis Syndrome - Longitudinal case series and individual case reports
CHS is a recurrent disorder interspersed with symptom-free intervals. It has been proposed to divide CHS into three phases: pre-emetic or prodromal, hyperemetic, and recovery phase [6
]. The prodromal phase can last for months or years with patients developing early morning nausea, a fear of vomiting, and abdominal discomfort [62
]. In this stage patients maintain normal eating patterns, and may increase or continue the use of cannabis because of the believed beneficial effects on relieving nausea [52
]. The hyperemetic phase is characterized by paroxysms of intense and persistent nausea and vomiting, commonly described as overwhelming and incapacitating. Patients vomit profusely, often without warning and can vomit and retch up to five times per hour [62
]. Most patients also present with diffuse but relatively mild abdominal pain. In one series approximately 70% of patients reported marked weight loss of at least 5 kg during their illness [6
]. In the emergency department patients are found to be dehydrated but hemodynamically stable. They undergo an extensive diagnostic work up, including laboratory and imaging studies which, in the majority of cases, are unrevealing. During the hyperemetic phase patients stereotypically take numerous hot showers throughout the day. This idiosyncratic behavior appears to be learned and is repeatedly used as the only alleviating measure to control symptoms and rapidly becomes a compulsive behavior. The recovery phase can last for days, weeks, or months and is associated with relative wellness and normal eating patterns. Weight is regained and bathing returns to regular frequency.
Patients with CHS usually remain misdiagnosed for a considerable time period. In one case series the average number of emergency room visits (7.1 ± 4.3) prior to diagnosis and the delay in diagnosis (for up to 9 years) was substantial [62
]. Not surprisingly, the early identification of patients with CHS leads to a reduction in morbidity and costs [6
]. The differential diagnosis of nausea and vomiting is extensive and includes a broad range of pathologic conditions affecting the gastrointestinal tract, the peritoneal cavity, CNS, as well as endocrine and metabolic functions [63
]. The initial approach to evaluate a patient with cyclical vomiting should start by excluding these vast disorders. In this context a comprehensive history along with initial screening tests should be performed to exclude acute conditions and emergencies (e.g pancreatobiliary disease, intestinal obstruction, pregnancy, etc). This includes laboratory tests (complete blood count and differential, glucose, basic metabolic panel, pancreatic and hepatic enzymes, pregnancy test), urinalysis, urinary drug screen, and plain flat radiographic series [63
Further imaging and invasive testing must be tailored to the individual presentation. For example, associated symptoms like hematemesis should prompt an upper endoscopy, neurological findings would support brain imaging, and pronounced abdominal tenderness justifies an abdominal CT or abdominal radiographic series [64
]. In the absence of positive findings on these diagnostic workups the possibility of an underlying motility disorder such as gastroparesis, intestinal pseudo-obstruction or small bowel dysmotility should be considered [63
In clinical practice CHS is most often confused with cyclic vomiting syndrome (CVS). In fact patients with CHS are often mislabeled as having CVS and vice versa. Confusion exists in the medical literature secondary to a failure to recognize chronic marijuana use as a source of vomiting. For example, in two recently published series of adult patients with CVS, approximately one third of patients reported daily marijuana use [65
]. Based on the categorization of functional disorders developed by Rome III, chronic marijuana use (CHS) is recognized as a mechanism for nausea and vomiting distinct from CVS [67
]. Although both conditions share an astonishing similarity, there are several significant differences. For example, CVS patients usually have important psychological comorbidities including depression and anxiety [64
]. In addition, CVS patients have a high prevalence of migraine headaches or a family history of migraines. Furthermore, gastric emptying rates in patients with CVS are often accelerated rather than delayed [46
]. summarizes some of the epidemiological and clinical characteristics that may help distinguish CVS and CHS.
Comparison of cyclic vomiting syndrome in adults and cannabis hyperemesis syndrome