Monday Medical: Allergic to penicillin? Probably not | SteamboatToday.com

Monday Medical: Allergic to penicillin? Probably not

Kristen Fahrner, M.D./For Steamboat Today

At every doctor's visit, you're asked to report allergies to medications. Maybe you remember your mom saying you had a rash while taking penicillin, so you diligently mark that down as an allergy.

But if you're not actually allergic, you may end up dealing with unnecessary negative consequences.

Penicillin is often the first choice of treatment for many bacterial illnesses, such as strep throat and sinus infections, so now your doctor must choose a different class of antibiotics for you. When picking up the alternate antibiotic at the pharmacy, you are shocked by the price. You're also a little worried about the risk of tendon rupture your doctor mentioned when prescribing this expensive antibiotic.

Don't be surprised if you find yourself wondering, "Am I really allergic to penicillin?" Chances are, you're not.

A whopping 10 percent of our population thinks they are allergic to penicillin, but it is now known that about nine out of 10 of these people are not truly allergic.

Why the confusion? Rashes, in particular, lead to misdiagnosis. In many instances, developing a rash while taking penicillin isn't a result of the antibiotic, but rather of the underlying viral or bacterial illness.

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Also, unlike other types of allergies, many people actually outgrow their allergy to penicillin. A recent study by the Mayo Clinic showed that, of 778 children with a history of penicillin allergy, 90 percent tested negative to the allergy. Similar studies in adults show that up to 94 percent tested negative.

While true penicillin allergic reactions are uncommon, they can be serious. If you have experienced severe reactions such as anaphylaxis, Stevens-Johnson syndrome or toxic epidermal necrolysis, you should not be tested.

If you've had more mild reactions, such as rashes or an unclear allergy history, or if it's been more than five years since your reaction, allergy testing is recommended.

Penicillin is often most effective in treating bacterial illnesses and is the first choice in your doctor's treatment algorithm. Penicillin has fewer side effects and is generally better tolerated than alternate antibiotics, which can cost up to eight times more than generic penicillin. And the use of stronger antibiotics can lead to bacterial resistance, making it harder for antibiotics and your body to fight infections in the future.

Testing for penicillin allergy is remarkably easy and can be done in an hour or two. First, you'll receive a prick test on your forearm. If you are allergic, your skin will form an itchy bump, similar to a mosquito bite, and no further testing is required.

If you don't get a bump, small drops of penicillin are placed beneath the skin at various concentrations. If this testing is also negative, your physician may give you an oral amoxicillin, which is a penicillin-based tablet, and observe you for an hour. If this is tolerated, we can say with 98-percent certainty you can take penicillin in the future.

"It's very satisfying after such a quick, simple test to notify the patient's primary care doctor that they are no longer considered allergic to penicillin," said Anya Gunn, a Steamboat Springs nurse who works with allergy patients. "It opens up so many new options in case the patient gets sick in the future."

So what is the bottom line? If "I’ve had a rash with penicillin" or "My mom told me I was allergic" sound familiar to you, consider the benefits of penicillin allergy testing, and discuss them with your doctor to see if you are a candidate.

Kristen Fahrner, M.D., of Northwest Colorado Ear, Nose, Throat & Facial Plastic Surgery in Steamboat Springs, is a board-certified otolaryngologist and member of the American Academy of Otolaryngic Allergy.