Hair analysis in pediatric cannabis intoxication is limited by possible sudoral self-contamination, especially in young children due to hair porosity. However, adult studies show no THC-COOH in sweat, challenging this hypothesis. THC-COOH presence in sweat has to this day never been studied in young children. Its absence would help assess the reliability of hair testing for prior exposure. Thus, our main objective is to describe whether THC-COOH can be detected in sweat following cannabis intoxication using gold standard techniques.

In cases of pediatric cannabis intoxication, hair analysis is frequently used to assess prior exposure. However, in young children, especially under 3 years old, hair porosity raises concerns about external contamination, notably through sweat. It has been hypothesized that cannabinoids could migrate into the hair via sweat shortly after ingestion, leading to self-contamination and potentially compromising the interpretation of results. This is particularly relevant when trying to distinguish acute ingestion from chronic exposure. In adults, several studies have shown no detectable sudoral concentrations of THC-COOH, the main metabolite used in hair testing, suggesting that such contamination is unlikely. However, due to developmental differences in pharmacokinetics, these findings cannot yet be extrapolated to children. Confirming the absence of THC-COOH in pediatric sweat would strengthen the validity of hair testing as a retrospective exposure tool.

This study would be performed on young children admitted to the emergency department for accidental cannabis intoxication. Sweat would be collected at inclusion using a similar procedure to a sweat test by stimulating sudation using pilocarpine and mild electrical stimulation. Cannabinoids would be analyzed by liquid chromatography coupled with mass spectrometry (LC-MS), which is the gold standard technique.

Follow-up would be simple, consisting in a single consultation 1 to 2 months following inclusion. This consultation is part of the usual medical care for young children following cannabis intoxication.

Inclusion Criteria:

• Child admitted to the Specialized Emergency Pole (POSU) and pediatric medico-surgical emergencies for acute cannabis intoxication.
• Child older than 3 months and younger than 3 years.
• Holders of parental authority, affiliated with or beneficiaries of a social security system.

Exclusion Criteria:

• History of cannabis intoxication identified during the interview and/or consultation of the medical record.
• Contraindication to sweat sampling (described in section 6).
• Absence of hair and/or hair length < 1 cm at the time of inclusion.
• Ongoing breastfeeding (exclusive and mixed).
• Inability to provide study-related informations to the holders of parental authority.