[Investigation of penicillin allergy. Procedures and retrospective statement of results for the period 1997 to 2001].

INTRODUCTION

We describe procedures in and findings of investigation for allergy to penicillin as it was performed at the Dermatological Department and the Allergy Centre of Odense University Hospital in the 5-year period 1997-2001 and compare history with findings on skin tests and systemic challenge.

MATERIAL AND METHODS

Retrospective evaluation of findings in the investigation of penicillin allergy. A total of 109 patients with a history of reaction to treatment with penicillins and a negative specific IgE for penicillins G and V were successively skin prick tested, intracutaneously skin tested, challenged orally and by intramuscular injection. Further testing was cancelled when a positive result occurred.

RESULTS

Fifteen of 109 (13.7%) had positive reactions on investigation. There was no correlation between the type and severity of cutaneous or systemic reactions to penicillin or presence of other allergies and test positivity or negativity. 20% of the test-positive developed severe systemic reactions (respiratory, cardiovascular) upon systemic challenge.

DISCUSSION

13.7% in a selected patient material with a history of penicillin allergy and negative specific IgE were found to have reaction to penicillin upon investigation. A high percentage of patients (20%) experienced systemic reactions to provocation. This finding has resulted in new procedures for the investigation of allergy to penicillin in our clinic.