A DOSE-DEPENDENT DELAYED-HYPERSENSITIVITY REACTION TO ACETAMINOPHEN AFTER REPEATED ACETAMINOPHEN INTOXICATIONS

We report a case of a 29-year-old woman with a borderline personality disorder who presented with intentional substantial acetaminophen (par acetamol) overdosage on nine occasions during a period of 21 months. I n most cases, the patient presented at the hospital within 4 h after i ngestion and was treated with gastric lavage, activated charcoal, laxa tives and intravenous N-acetylcysteine, During the sixth overdosage th e patient developed a rash on her chest and shoulders which was consid ered an anaphylactoid reaction to N-acetylcysteine. Therefore she was treated with oral methionine subsequently, but developed the rash agai n. The rash was then ascribed to the repeated high-doses of acetaminop hen and treatment with N-acetylcysteine was reinstituted. This case sh ows that when an anaphylactoid reaction occurs after an acetaminophen overdose and treatment with N-acetylcysteine, acetaminophen must also be taken into account as the cause of the anaphylactoid reaction befor e effective therapy with N-acetylcysteine is withheld.