Résumé
An antibiotic allergic reaction represents one of the side effects of drugs and is a daily worry for the clinician. If urticaria and maculo-papular eruptions are the most frequent manifestations, then anaphylaxis can occur. The tools allowing a definite diagnosis are validated for some antibiotics and include the following procedures: a thorough clinical history, standardized skin tests, reliable biological tests, and drug provocation tests. When properly performed in specialized centers, a firm diagnosis is often possible and safe alternative medication can be proposed. This is particularly the case for beta-lactam antibiotics, considering their wide prescription and utility.