Provocation tests in drug allergy

Almost two-thirds of patients who visit a doctor for a reaction that is diagnosed as a ‘drug allergy’ (DA) are not allergic. This false claims of drug allergy leads to unnecessary avoidance of fi rst choice drugs, exposes the patient to less effective and potentially more toxic drugs, increases healthcare costs, and contributes to the development of antibiotic resistance. Therefore, a drug allergy evaluation at a specialized center must be offered to all patients with suspected drug allergy. Drug allergy evaluation comprises patient’s history, in vivo skin testing (prick, intradermal and patch tests), in vitro and provocation tests. Skin tests have been validated for penicillins, muscle relaxants and carboplatin and can also be useful with some other drugs, including iodinated contrast media (ICM) and anticoagulant drugs. Most in vitro studies have not been suffi ciently evaluated to be used as standard investigation outside the context of prospective studies. Drug provocation tests (DPT) are often considered an unnecessary and dangerous method for drug allergy evaluation. In this reviews we present the updated indications for DPT and the safety data concerning DPT. We conclude that DPT is a safe procedure if performed in specialized centers. There are no accurate alternatives in most cases. DPT remains the gold-standard to validate alternative diagnostic methods. Provocation tests in drug allergy Luís Araújo1, Pascal Demoly2 1 Serviço de Imunoalergologia, Hospital Universitário de São João, Porto, Portugal. He is the corresponding author. 2 Allergy Department – Maladies Respiratoires – INSERM U657, Hôpital Arnauld de Villeneuve, University Hospital of Montpellier, France. R e v P o r t I m u n o a l e r g o l o g i a 2 0 0 9 ; 1 7 ( 4 ) : 3 1 5 3 2 4 Data de recepção / Received in: 01/07/2009 Data de aceitação / Accepted for publication in: 15/07/2009