Penicillin Allergies May Be Fake-News

The vast majority of patients reporting a penicillin allergy are not actually allergic when tested correctly, reports a new study.

Since penicillins are the safest and most effective antibiotics for many infections, it is important to find out if a patient is really penicillin allergic.

The label of penicillin allergy is commonly attached in childhood where common childhood infections may themselves contribute to or be confused with an allergy.

This University of California San Diego (UCSD) study estimated 25 million Americans self-report penicillin allergy, and up to 98 percent of these claims were found to be non-allergic, after penicillin allergy testing.

According to George Sakoulas MD, with the UCSD School of Medicine and colleagues said: “Although it is common for a patient to declare a drug allergy, treating clinicians must verify the penicillin allergy by taking a thorough history and if deemed necessary, test for a Type 1 reaction.”

This test involves pricking the skin with two forms of penicillins and a subsequent intradermal test.

If these tests are negative, it is very unlikely that a penicillin allergy is present, says the American Academy of Allergy Asthma & Immunology.   

In many instances after negative testing, a dose of an oral penicillin is also given, followed by an observation period. If there is no reaction, the patient is not at risk of having a serious immediate reaction. 

Additionally, penicillin allergy testing has been shown to significantly reduce future annual healthcare expenditures.

This study showed that a penicillin allergy identity could translate into an average excess cost of $1,145 to $4,254 per patient for outpatient and inpatient drug costs and inpatient hospitalizations.

Additionally, supporting the clinical relevance of these economic impacts are recent clinical analyses that show worse outcomes in patients with reported penicillin allergies who receive non-beta lactam antibiotics when compared to their non-penicillin allergic counterparts.

This is particularly relevant in the treatment of Staphylococcus aureus bacteremia. 

No conflicts of interest were disclosed by these researchers.