- Retrospective evaluation of the clinical course of carbamate poisoning in young children and adults. Thirty-six children aged 1 to 8 years (median 2.5 years) and 24 adults aged 17 to 41 years (median 22 years) ingested rat poison resulting in carbamate poisoning. The ingested poisons in all cases were positively identified as methomyl or aldicarb by gas chromatography-mass spectrometry. Symptoms of intoxication in children were compared to those in adults with similar depression of the serum cholinesterase. The predominant symptoms in young children were central nervous system depression and hypotonia. The most common muscarinic effect was diarrhea. In adults, the main signs were miosis and fasciculations. Fasciculations in children were less frequent. Central nervous system depression, hypotonia, and diarrhea were uncommon in adults. Based on a relatively large number of carbamate poisonings in young children, we conclude that the clinical presentation differs from adult poisoning manifestations. The absence of classic muscarinic effects does not exclude the possibility of carbamate poisoning in young children with central nervous system depression.