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Beyond the Major Determinant: Patterns of Penicillin Skin Test Positivity
Ingrid Salciccioli1, Andrew J King2, John J O Accarino1
1Division of Allergy and Clinical Immunology, Mass General Brigham, Boston, MA; Rheumatology and Allergy Clinical Epidemiology Research Center, The Mongan Institute, Massachusetts General Hospital, Boston, MA; Harvard Medical School, Boston, MA.
Summary
Penicillin skin testing effectively identifies most penicillin allergies. The PREPEN test is not essential for routine evaluations and can be reserved for specific situations.
Area of Science:
- Immunology
- Clinical Medicine
- Pharmacology
Background:
- Adverse drug reactions to penicillin are common.
- Accurate diagnosis of penicillin allergy is crucial for patient safety and appropriate antibiotic selection.
- Penicillin skin testing (PST) is a key diagnostic tool.
Purpose of the Study:
- To evaluate the diagnostic utility of PST with penicillin G and aminopenicillins.
- To assess the role of the penicillin skin test reagent (PREPEN) in allergy evaluation.
- To compare PST with direct oral challenge in low-risk patients.
Main Methods:
- Retrospective chart review of patients undergoing penicillin allergy evaluations.
- Analysis of skin test results using penicillin G and various aminopenicillins.
- Comparison of skin test results with documented clinical outcomes and challenge data.
Main Results:
- Penicillin G and aminopenicillin skin testing identified nearly 90% of patients with confirmed penicillin allergy.
- PREPEN did not significantly improve the diagnostic yield compared to standard PST reagents.
- Direct oral challenge remains a safe and effective method for low-risk patients.
Conclusions:
- Standard penicillin and aminopenicillin skin testing are highly effective in diagnosing penicillin allergy.
- PREPEN may not be necessary for most routine penicillin allergy evaluations.
- Skin testing strategies remain valuable, with direct oral challenge preferred for low-risk individuals.
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