Penicillin Allergy Is Overstated

Nine Out of Ten Who Think They're Allergic Are Not(1)

Mar 07, 2016, 09:07 ET from PRE-PEN

ROUND ROCK, Texas, March 7, 2016 /PRNewswire/ -- Are you really allergic to penicillin? Odds are against it, according to new information from the U.S. Centers for Disease Control and Prevention (CDC), which has issued a factsheet on penicillin allergies on its "Get Smart on Antibiotics" website.

Ten percent of all U.S. patients report being allergic to penicillin, but only a small fraction – less than 1 percent – of the entire population is truly allergic.2 An estimated 80 percent of patients with a confirmed penicillin allergy lose their sensitivity after 10 years3, the CDC notes in its fact sheet.

Misinformation about penicillin allergy has widespread implications. Patients who report being penicillin‐allergic incur higher healthcare costs, studies show, and are significantly more likely to receive fluoroquinolones, vancomycin, and clindamycin (broad‐spectrum antibiotics) than non‐ allergic patients.4 These medications are part of a class of antibiotics that are being overprescribed, which may contribute to antibiotic resistance.

"Before prescribing broad‐spectrum antibiotics to a patient thought to be penicillin‐allergic, evaluate the patient for true penicillin allergy (IgE‐mediated)," the CDC notes, "by conducting a history and physical, and when appropriate, a skin test and challenge dose." The CDC provides antibiotic stewardship information as part of its Get Smart campaign.

"Unverified penicillin allergies are a significant public health problem and all hospitalized patients with a penicillin allergy should have their allergy confirmed by skin testing or removed from their record," says Eric Macy, MD FAAAAI, Kaiser Permanente. "Otherwise, they will potentially receive less effective antibiotics that may cause more side effects and can lower the resistance to serious infections such as Clostridium difficile."

Peggy Lillis who was a 56‐year‐old kindergarten teacher from Brooklyn NY was given clindamycin as a prophylactic measure after a routine dental procedure. Since she was not allergic to penicillin, the use of clindamycin left her unnecessarily vulnerable to a Clostridium difficile infection (CDI), with deadly consequences. "My mother's death from a CDI illustrates that using antibiotics do carry risks," said Christian John Lillis, Executive Director Peggy Lillis Foundation. "Being labeled as penicillin allergic increases your risk of CDI and antibiotic resistant infections. We started the Peggy Lillis Foundation to combat CDIs and believe that Americans knowing if they're penicillin allergic is an important way to minimize their risk for serious infections," Lillis continued. The CDC reports that CDI was linked to 29,000 deaths in 2011. Those who take antibiotics and are also receiving medical care are most at risk for the infection, especially older adults.

The overuse of broad spectrum antibiotics is so prevalent that the CDC estimates there are 8 million additional days that Americans spend in hospitals annually. Antibiotic resistance results in $20 billion per year in excess health care costs and $35 million more in other societal costs, according to the CDC.5

For more information on penicillin skin testing visit

1, 2, 3, 4 Joint Task Force on Practice Parameters representing the American Academy of Allergy, Asthma and Immunology; American College of Allergy, Asthma and Immunology; Joint Council of Allergy, Asthma and Immunology. Drug allergy: an updated practice parameter. Ann Allergy Asthma Immunol. 2010 Oct;105(4):259‐273.

5 Centers for Disease Control and Prevention,