A pseudoencephalitis presentation of a pediatric non-intentional intoxication

We report a case of a pseudo encephalitis presentation of pediatric intoxication - Case report - a 7 year-old girl was admitted to our pediatric emergency unit after she developed sudden agitation, visual and tactile hallucinations. She was febrile (38.3 °C). She had not experienced any recent head trauma, infection or toxic ingestion; she did not take any medication for ADD. Her physical exam revealed tachycardia, normal pupils, reflexes and normal plantar responses. Laboratory investigations (complete blood count, basic metabolic panel, plasma lactate level, ammonia level) produced normal results. Lumbar puncture and computed tomography of the brain were normal. A serum and urine drug screening (benzodiazepines, barbiturates, cocaine, cannabis, amphetamines, methadone, ethanol) was negative. An electroencephalogram, performed during an episode of hallucinations, was compatible with benzodiazepine intoxication. A larger toxic detection by liquid chromatography/diode array detector (LC-DAD) detected promethazine and its metabolites. Symptoms lasted 20 h and she finally said she drank syrup from an over-the-counter cough suppressant medication. Comments - Anticholinergic syndrome is not well recognized or evoked in children presenting hallucinations. Promethazine is still present in several over-the-counter medications, alone or in combination with acetaminophen, carbocisteine or opiates.

Conclusion: Medications containing promethazine should not be prescribed in children. Such intoxication can mimic encephalitis.