Methods: In this prospective, open-label, controlled, multi-clinical trial, 8702 individuals from primary care clinics were screened for penicillin allergy. 169 patients with a history of non-life threatening allergic reaction to penicillin, dating back at least 3 years, were recruited for study. Regardless of the response to penicillin skin testing, patients received the recommended daily dosage of penicillin and amoxicillin on two separate occasions. 2-6 years later a follow-up was conducted to assess the outcomes of further penicillin administration.