Have You Been Labeled with a Penicillin Allergy?

Written by:  A.H. Bagenstose, MD Board-Certified Allergist

Did you know that approximately 10-13% of the population has been labeled with a penicillin allergy but may not actually have one? Studies have shown only about one percent of the population has a true penicillin allergy!

That’s quite a difference.

Why are so many patients labeled with an allergy if they don’t really have one?

Medical providers were taught to use extreme caution if a patient showed any intolerance to penicillin, it’s a conservative action to just label the intolerance as an allergy; it’s safer, right? New studies have found that the mislabeling of patients with a penicillin allergy has actually led to health problems and increased community resistance to antibiotics. Yikes! The other reason for such a high number of mislabeled penicillin allergies is that over a period of about ten years, 80% of true penicillin allergies are lost.

Why does the overuse of penicillin allergy labeling cause so many problems?

Healthcare providers prescribe broader-spectrum antibiotics when they see a patient with a “penicillin allergy.” These broad-spectrum antibiotics are less targeted, which can lead to less effective treatment overall. These drugs can cause more side effects, such as increased incidence of toxicity and pseudomembranous colitis (swelling or inflammation of the large intestine due to an overgrowth of C. difficile bacteria) which has a two percent mortality rate. Using broad-spectrum antibiotics where penicillin would suffice in a non-allergic patient is kind of like dumping a bucket over someone’s head instead of just wiping a crumb off the edge of their lip!

What are the symptoms of a true allergy?

True allergic reactions usually occur within one hour of exposure and typical allergic symptoms include hives, difficulty breathing, and anaphylaxis. Headache and gastrointestinal symptoms are usually signs of intolerance and not an allergic reaction, and while rashes may be a symptom of an allergy, many times they’re actually caused by a virus and misdiagnosed as an allergy to penicillin.

How can I find out if I have a true penicillin allergy?

You can be tested by an allergist to find out for sure. This is done safely in the office, under the direct supervision of a board-certified allergist. The test consists of a series of simple procedures starting with a scratch skin test. If the scratch tests are negative, intradermal testing is done, which consists of a small amount of penicillin allergen put just under the surface of your skin. If no reaction is seen, then the patient is given small increments of penicillin by mouth. If all tests are negative and the penicillin is tolerated well, then the patient is de-labeled from having a penicillin allergy. This means they may now be prescribed penicillin to avoid broader spectrum antibiotics, resulting in more “targeted” therapy with possibly fewer side effects.

Who can get tested for a penicillin allergy?

Penicillin testing is safe and recommended for all patients labeled with a penicillin allergy. In fact, it is safe enough to perform on pregnant women and is actually encouraged by the American College of Obstetricians and Gynecologists for women who are pregnant or considering pregnancy, as penicillin is safer and more effective for both the patient and baby than broad-spectrum antibiotics. The only exceptions are patients who have had a true reaction to penicillin within the last five years, those who have had recurrent reactions to penicillin, or severe reactions such as Stevens-Johnson syndrome or toxic epidermal necrosis.

Delabeling is one step toward safer antibiotic use overall in the future.

If you’re interested in being tested and possibly being de-labeled with a penicillin allergy, call 614-299-7546 for an appointment.