Background: Acetaminophen is the most common drug involved in pediatric poisonings, both intentionally and accidentally, and is the leading cause of acute liver failure among all age groups.

Objectives: To define the characteristics of patients admitted to a pediatric emergency department (ED) where serum acetaminophen concentrations were measured, and to determine which variables are associated with significant risk of acetaminophen toxicity.

Methods: Acetaminophen serum concentrations were measured, in a retrospective case series, of patients younger than 18 years who had been admitted to the ED at Shamir Medical Center between 1 January 2008 and 31 December 2015.

Results: During the study period 180,174 children were admitted to the ED. Acetaminophen serum concentrations were measured in 209 (0.12%) patients. Mean age was 12.4 ± 5.9 years. Elevated liver enzymes were found in 12 patients, 5 of whom had documented acute liver injury. All five were older than 11years.Two cases of acute liver injury were attributable to acetaminophen ingestion. In both cases the cause was intentional overdose. Univariate analysis showed a significant (P < 0.05) correlation between detectable acetaminophen blood level and a positive history of drug or acetaminophen ingestion, and suicide attempt. Not all children with non-severe acetaminophen poisoning had been diagnosed during the study period. A positive history of acetaminophen ingestion was associated with a 28-fold higher risk for detectable acetaminophen blood level.

Conclusions: In the absence of a positive history of acetaminophen ingestion and in young children with accidental intoxication, the risk of hepatotoxicity is relatively low.