Drug Allergy

Antibiotic allergy skin testing and graded challenge procedures: If you require penicillin or any other beta lactam antibiotic, but have an allergy to this medication class listed in your medical record, you may still be able to receive the medication without complications.

While patient reported antibiotic allergies are relatively common (for example, about 10 percent of people report a penicillin allergy), the incidence of true sensitization is significantly lower. This is either because the reaction was not truly allergic in nature to begin with, or because their allergy has resolved over time.

Identification of tolerance to these antibiotics is important because otherwise, patients are unnecessarily exposed to alternative, often less effective, antibiotic classes. This also favors the development of antibiotic resistance.

For a documented penicillin allergy in particular, a validated skin test is available that rules out true sensitization with extremely high accuracy. If the skin test is negative, this is followed by an oral challenge with a full dose of amoxicillin to ensure tolerance.

In the setting of other antibiotic allergies, skin testing has not been substantiated by a large body of evidence. However, even in these cases, graded drug challenges have been successfully employed with a documented high safety rate, when selected according to patient histories with a low likelihood of true reactivity. These challenges can extend from hours to days to weeks, all depending on the evolution of the prior reaction.

Even if the history suggests a low likelihood of clinical reactivity, all of these procedures will be performed under close monitoring and supervision for any adverse reactions, to ensure that a full dose can be tolerated and that the allergy can be safely deleted from the medical record.

Penicillin Skin Test/Challenge

Patients who may have previously had an allergic reaction to penicillin may no longer be sensitive to the medication, and may benefit from a penicillin allergy test if they require penicillin for medical treatment. During an initial consultation, our physicians will evaluate your medical and penicillin sensitivity history, and thereby determine candidacy for further testing.

At a subsequent visit, if deemed eligible, skin prick tests and intradermal tests with standardized reagents will be performed, and should these be negative, an open challenge with an oral form of penicillin will be performed under close physician supervision.