To analyze published reports of unintentional cannabis ingestions in children to determine presenting signs and symptoms, route of exposure, treatment, and outcome.

PubMed, OpenGrey, and Google Scholar were systematically searched. Articles were selected, reviewed, and graded using Oxford Center for Evidence-Based Medicine guidelines.

Of 3316 articles, 44 were included (3582 children age ≤12 years). We found no high quality (Oxford Center for Evidence-Based Medicine level I or II) studies and 10 level III studies documenting lethargy as the most common presenting sign and confirming increasing incidence of unintentional ingestion in states having decriminalized medical and recreational cannabis. We identified 16 level IV case series, and 28 level V case reports with 114 children, mean age 25.2 ± 18.7 months, range 8 months to 12 years, and 50 female children (44%). The most common ingestion (n = 43, 38%) was cannabis resin, followed by cookies and joints (both n = 15, 13%). Other exposures included passive smoke, medical cannabis, candies, beverages, and hemp oil. Lethargy was the most common presenting sign (n = 81, 71%) followed by ataxia (n = 16, 14%). Tachycardia, mydriasis, and hypotonia were also commonly observed. All cases were cared for in the emergency department or admitted, and mean length of stay was 27.1 ± 27.0 hours. Twenty (18%) were admitted to the pediatric intensive care unit, and 7 (6%) were intubated.

Unintentional cannabis ingestion by children is a serious public health concern and is well-documented in numerous studies and case reports. Clinicians should consider cannabis toxicity in any child with sudden onset of lethargy or ataxia.