Case Presentation: A 41-year-old female presented with a three-day history of nausea, vomiting, and diffuse abdominal pain radiating to her back. The day prior to admission, the patient started having hematemesis, characterized as “streaks” of blood in her emesis. The patient had recently been in a motor vehicular accident leading to a tibial plateau fracture for which she was given tramadol for pain; she started using increased amounts of marijuana once she ran out of tramadol. The pain improved with marijuana use and hot showers, but worsened with ingestion of food or liquid. Morphine and fentanyl were given to the patient in the emergency department but did not relieve her pain. Ondansetron and prochlorperazine were given but did not relieve her nausea. A lipase level to investigate acute pancreatitis was normal. A CT scan of her abdomen for acute abdomen yielded benign results. A right upper quadrant ultrasound revealed no cholecystitis or acute biliary obstruction. While this work-up was obtained, capsaicin cream was administered to the patient which improved the all the patient’s symptoms.
Discussion: Abdominal pain is a common but sometimes enigmatic chief complaint in the emergency department which has a plethora of possible etiologies. Cannabinoid hyperemesis syndrome is an increasingly recognized cause of ER visits. While medical cannabinoids act as anti-emetics by antagonizing 5-HT receptors and dopamine release in the gut and brain, respectively, chronic cannabinoid use paradoxically promotes a pro-emetic state by theoretically downregulating the cannabinoid receptors throughout the body. Interestingly, cannabinoid hyperemesis syndrome can masquerade similarly to other potentially life-threatening conditions such as acute pancreatitis, biliary obstruction, and esophageal tears – conditions considered amongst others in this patient initially. Given the patient’s long history of marijuana use with recent exacerbation and stress (motor vehicular accident), the decision was made to administer capsaicin. Though initially thought to deplete substance P, a neuroendocrine regulator of pain nociception, capsaicin is now thought to primarily act in pain relief as well as reversal of cannabinoid hyperemesis by persistently activating calcium release into cells through the TRPV1 channel, a channel that promotes the sensation of burning and the reduction of nausea. This continuous rather than episodic signaling ultimately “defunctionalizes” and inhibits pain signaling at nerve endings.
Conclusions: Cannabinoid hyperemesis syndrome can mimic characteristics of more worrisome causes of abdominal pain. Given an appropriate history, a cost-effective and timely treatment option can be found in capsaicin cream that can be trialed in the ED while other work-up is pending. This may even reduce length of stay and costly work-up.