Medical charts are supposed to contain the cold, hard facts of our health: conditions, medications, surgical and family history, and allergies.
Many people mistakenly believe they’re allergic to penicillin— a workhorse class of antibiotics that treats ear infections, strep throat, and more—when in reality, only a small number truly are.
“Even though a good 10 percent of Americans are labeled with penicillin allergy, less than 1 percent have a true allergy to penicillin,” says UNC Health allergist Millie Kwan, MD, PhD.
And that leads to problems: You don’t get the most effective antibiotic for your infection, which can result in longer illnesses, more side effects and “superbugs” that don’t respond to antibiotics at all.
“There are a lot of negative outcomes to having penicillin allergy on your chart,” says Dr. Kwan, who encourages people to talk to their primary care doctors about the label and whether it’s warranted.
Signs and Symptoms of a Penicillin Allergy
If you are allergic to penicillin, you can experience severe symptoms shortly after taking the drug: hives, itching, breathing problems, wheezing, swollen throat, racing heart and decreased blood pressure. This extreme reaction, called anaphylaxis, can be fatal. In very rare cases, penicillin allergy can be delayed days or weeks after taking the drug.
But many people who are labeled as allergic to penicillin never experienced any of these symptoms from penicillin, Dr. Kwan says.
When today’s adults were children, doctors worried less about overprescribing antibiotics. A penicillin such as amoxicillin was often given for what was probably a viral infection, but antibiotics only work for bacterial infections.
The child taking the medicine might have had a rash because that’s common in kids with viral infections, and that rash was wrongly noted as an allergic reaction. Or, a child taking penicillin experienced stomach upset or diarrhea, which is common with antibiotics, and that was labeled an allergy. Sometimes a parent would forget which child reacted poorly to penicillin, and so they’d just put “do not prescribe” on all their kids’ charts.
“We need to teach everyone that those aren’t allergies, and we should get rid of those as allergies on people’s charts,” Dr. Kwan says.
Even if you had an allergic reaction once to penicillin, it doesn’t necessarily mean you are at risk today. Dr. Kwan explains that only half of people who had a bad reaction are still reactive after five years; less than 10 percent will be reactive after 20 years.
“Folks think once you get labeled with a penicillin allergy, that’s it, but that’s a myth,” she says. “This is not typically a forever thing, and you want access to penicillin if you can have it.”
The Problem with Avoiding Penicillin
Penicillin is one of the oldest antibiotics, but it’s still among the most commonly prescribed today. Amoxicillin is used to treat pneumonia, bronchitis, urinary tract infections and many other bacterial infections.
If amoxicillin is the best drug for your infection but you think you’re allergic, your doctor resorts to a backup that might be less effective, cause more side effects or leave some of the problem bacteria to reproduce in your body. This contributes to the problem of superbugs that are resistant to antibiotics.
“You want to ‘clear the field’ with the antibiotic from the get-go,” Dr. Kwan says. “If you don’t use the right antibiotic, it’s survival of the fittest when it comes to bacteria. You leave the strongest.”
That’s bad news for your body the next time you encounter those bacteria and also for the healthcare system at large, as superbugs spread.
Talk to Your Doctor About Penicillin Allergy
If you believe you might have a penicillin allergy or if your medical chart indicates one, talk to your doctor about the evidence. You may be part of the tiny minority who cannot take these antibiotics, or you may be mislabeled. You and your doctor can decide what steps to take to find out.
Some people, particularly those who have had reactions to penicillin years ago, benefit from allergy testing, Dr. Kwan says. This can include a skin test or taking a dose of amoxicillin in the safety of an allergy clinic.
It’s especially important for pregnant women to figure out if their penicillin allergy status may be inaccurate, Dr. Kwan says, because of group B strep. About 1 in 4 women carry this common bacteria, which can be passed to their newborn and cause life-threatening complications. When doctors know a woman carries group B strep, she is given intravenous antibiotics during labor to protect the baby. Penicillin is the most effective for this job.
“They should come see us so we can remove incorrect labels and give them the best care,” Dr. Kwan says.
Wondering if you’re really allergic to penicillin? Talk to your doctor, or find one near you.