[Allergic reactions to paracetamol]

Paracetamol is an extensively used analgesic and antipyretic. Allergy to this drug is occasionally reported and is usually moderate.

We led a retrospective study of 119 cases of allergic reactions to paracetamol notified to the Tunisian centre of pharmacovigilance, between September 1990 and September 2000. These cases were validated according to the method of imputability of Bégaud et al.

Our population comprised 64 women and 55 men, aged 1 month to 70 years. Antecedents of allergy or atopy were found in many cases, including 10 cases of allergy to paracetamol and 6 to salicylates. Paracetamol was self-administered in 50% of cases and taken with other drugs in 68% of cases. The type of lesions varied, the most frequent being urticaria (34.4%), macular and pustular eruption (30.2%) and fixed drug eruption (12.6%). Some reactions were serious, such as Lyell syndrome or anaphylactic shock. Resolution was favourable in all cases and paracetamol was definitively contraindicated for patients with scores of high or mild imputability.

Allergy to paracetamol seems to be rare but not exceptional. Several risk factors seem to be important in triggering this side effect, particularly antecedents of allergy to this drug or to aspirin.