UConn Health experts are working to clear up the confusion around penicillin allergies
Many people have been told at some point in their lives that they are allergic to penicillin. But according to infectious disease experts at UConn Health, most patients carrying that label may not actually have a true allergy at all, and that misunderstanding could have significant consequences for both individual patients and public health.
"It's much more common for people to report a penicillin allergy than it is for them to truly have one," says Dr. Jessica Abrantes-Figueiredo, an infectious disease physician at UConn Health. "In reality, less than 1% of patients are likely to have a true penicillin allergy."
Penicillin is a class of antibiotic medications. Penicillin treats bacterial infections like strep throat, ear infections, and urinary tract infections. They work by attaching to and damaging the cell walls of bacteria. Types of penicillin include penicillin V, penicillin G, amoxicillin, and ampicillin.
Experts say many penicillin allergies are identified in childhood, often after a rash or illness that may have had nothing to do with the antibiotic itself. Others are based on family history or side effects that are not actually allergic reactions.
"One of the most common misconceptions is that if your parent had a penicillin allergy, you automatically have one too, and that's simply not true," Abrantes-Figueiredo says.
The issue is more important than many people realize. When patients are labeled as allergic to penicillin, providers often have to avoid an entire class of antibiotics and turn instead to broader-spectrum medications. Those alternatives can be less effective, more expensive, and carry greater risks of side effects.
"Patients often think, 'If I'm allergic, just give me something else,'" says Dr. David Banach, an infectious disease physician and hospital epidemiologist at UConn Health. "But those alternatives may not be the best treatment for the infection and can contribute to antibiotic resistance."
Antibiotic resistance occurs when bacteria adapt and become harder to treat with existing medications. It is a growing concern both nationally and globally. Infectious disease specialists emphasize the importance of antibiotic stewardship using antibiotics only when necessary and selecting the most targeted treatment possible.
Banach, who has helped lead antibiotic stewardship efforts at UConn Health, says the work ties directly into the issue of penicillin allergy labeling. Earlier this year, he discussed the growing importance of antibiotic stewardship and the dangers of antibiotic resistance in a separate UConn Today story.
"When we use antibiotics that are broader than needed, we can unintentionally encourage bacteria to become resistant," Banach says. "Good antibiotic stewardship helps protect both the individual patient and public health."
In addition to resistance concerns, alternative antibiotics can sometimes cause more serious complications. Certain medications may carry higher risks for side effects such as tendon injuries or Clostridioides difficile (C. diff) infections.
To help address the issue, UConn Health is developing a specialized clinical service focused on evaluating and potentially removing inaccurate penicillin allergy labels from patients' medical records.
The planned service would include detailed patient history reviews and, when appropriate, supervised oral amoxicillin challenges performed in a monitored clinical setting. In many low-risk patients, newer research suggests testing can safely determine whether a patient truly has an allergy.
"Sometimes, just taking a detailed history is enough to determine that a patient likely isn't allergic," Abrantes-Figueiredo says. "Other times, we can safely test patients and potentially remove that allergy label."
During an oral challenge, patients receive a small dose of amoxicillin and are closely monitored for any reaction before receiving the remainder of the medication. Severe reactions are considered extremely rare, and the testing is performed in a setting equipped to manage allergic responses if needed.
The effort also includes educating healthcare providers and staff on the difference between true allergies and medication intolerances.
"A lot of medical records simply say 'penicillin allergy' without any details," Banach says. "Improving documentation and helping patients better understand their own histories is an important part of the process."
The team hopes the future service will help patients gain access to safer, more effective first-line antibiotics while supporting broader efforts to combat antibiotic resistance.
For now, experts encourage patients who believe they may have a penicillin allergy to speak with their primary care provider about their history and whether further evaluation may be appropriate.
