Lack of risk of sensitization due to the diagnostic procedures (skin test and challenge) in patients with history of recent allergic reaction to amoxicillin

Abstract

Rationale To evaluate the risk of sensitization in subjects with history of amoxicillin (AX) allergy after they are challenged with a 3 days-course of oral amoxicillin administration. Methods We selected 16 subjects (6 males and 10 females; range 7-67 years) with history of recent (range: 6 months-5 years) allergic reaction to AX and negative skin prick and intradermal tests for PPL, MDM and AX. A 3-days course of oral AX was carried out in all patients. This drug was administered from 62,5 mg up to 1000 mg (500 mg in children). The patients were carefully monitored during the 3-days challenge for symptoms compatible with an allergic reaction. The tests were performed in a single blind fashion. Complete equipment for cardio-pulmonary resuscitation was always available in our clinic. After 30 days the same skin tests were repeated in all subjects. Results The 3-days oral challenge with AX proved negative in all patients. No late reactions were observed. All patients remained negative to the repeated skin tests after 1 months. Conclusions Our data suggest that skin prick test could be useful in the selection of patients with false allergic reactions to AX. Because the skin test to AX remained negative after a previous AX skin test and a 3-days oral challenge, we can conclude that there is no risk of sensitization with the use of these diagnostic procedures.