Allergic to penicillin
About 20 years ago, when I was barely out of college and a struggling journalist, I developed a horrible sore throat. I didn't have a regular doctor, so I had my throat examined in a small clinic in a strip mall. The doctor figured I had strep throat, but the test came back negative. Still, she prescribed antibiotics and sent me on my way. The next morning, I woke up with little red dots all over my body, so I went back to the clinic. The same doc looked at me, said I had hives, harrumpfed that I was allergic to penicillin and gave me a prescription for a different antibiotic. The sore throat eventually went away, but every time since that I've gone to a doctor or dentist and I’ve listed penicillin as one of my allergies. Still, I always wondered if I really had an allergy; I took penicillin frequently during my childhood and never had an allergic reaction.
I came across a recent study published in the Annals of Emergency Medicine that said 80 to 90 percent of people who report being allergic to penicillin are really not.
This new study sought to determine how many patients who came into an Emergency Department (ED) and said they are allergic to penicillin really were allergic. Using two back-to-back skin tests, doctors in the ED at the University of Cincinnati tested 150 patients who reported having a penicillin allergy. 91 percent of these patients tested negative for the allergy.
For Dr. Joseph Moellman, an associate professor at the University of Cincinnati Department of Emergency Medicine, who conducted this study, finding out that taking the additional 30 minutes to conduct these two tests has several important implications. "We see a lot of patients with pneumonia, with sepsis, for which penicillin is a great drug...It's also a lot cheaper." Moellman says the average cost saving is $71. So if, for example, a pneumonia patient is in the hospital for a week, and possibly needs antibiotics every six hours – significant savings can add up very quickly. Plus, using penicillin where it's known to work allows doctors to save the few newer antibiotics we have for illnesses that have become resistant to penicillin.
"This is good information," says Dr. Clifford Bassett, an allergy expert and spokesperson for the American Academy for Allergy, Asthma and Immunology. "The fact that the test is fast and inexpensive is helpful." But he did point out that there has been a shortage of proper testing agents for penicillin. Once these testing agents become more widely available again, Bassett says that this test could be done in other settings too, not just in an emergency room, but also in a regular doctor's practice.
He adds that some previous research suggests that some people who genuinely were allergic to penicillin could lose their allergy if they don't come in contact with this drug for 10 years or more.
Of course neither doctor could explain whether I really am allergic to penicillin. But Moellman explained that sometimes a virus itself can cause hives, and Bassett told me that usually it takes more than 24 hours for a penicillin allergy to become evident. I, for one, plan to get tested to determine whether I truly am allergic to penicillin.
Have you been told you're allergic to penicillin? Would you consider getting tested?
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