Public Release: 

Which comes first: Self-reported penicillin allergy or chronic hives?

New study shows strong association between the two conditions

American College of Allergy, Asthma, and Immunology

ARLINGTON HEIGHTS, Ill. (February 3, 2016) - People who have self-reported penicillin allergy may have a three times greater chance of suffering from chronic hives. And people who have chronic hives tend to self-report penicillin allergy at a three times greater rate than the general population. Coincidence? Authors of a new study think not.

The study, in the Annals of Allergy, Asthma and Immunology, the scientific publication of the American College of Allergy, Asthma and Immunology (ACAAI), examined medical records of 11,143 patients seen at the University of Pennsylvania Health System Allergy-Immunology Clinic. Of those, 220 were identified as having both self-reported penicillin allergy and chronic urticaria (hives).

"We wanted to know if there was a correlation between self-reported penicillin allergy and chronic urticaria," said lead author and allergist Susanna Silverman, MD, ACAAI member. "We found higher than expected incidence compared to the general population, and we wondered if some patients who believed they had penicillin allergy might actually have chronic urticaria." Chronic urticaria is defined as hives - with or without swelling - that are present either continuously, or off and on, for longer than six weeks.

Many people have had an unfavorable response to penicillin - such as hives or swelling - at some point in their lives and are told they are allergic. Most have never seen an allergist and have never been tested for penicillin allergy. They are labeled "penicillin-allergic" on their medical history, and are given alternative antibiotics for infections.

"It's important for anyone who thinks they have a penicillin allergy to be tested by an allergist," said allergist and study author Andrea Apter, MD, ACAAI member. "If testing finds that someone with chronic urticaria and self-reported penicillin allergy isn't allergic to penicillin, it may be that their hives are simply due to chronic urticaria, or they may be more prone to rashes and hives throughout their lives, possibly due to increased skin sensitivity."

Allergists are experts in diagnosing and treating hives, and are trained to look for triggers. An allergist may recommend medications to prevent the hives or reduce the severity of symptoms. Whether the treatment is available only by prescription or over the counter will depend on several factors, including how uncomfortable the hives are making you.

For more information about both penicillin allergy and the treatment of hives, and to locate an allergist in your area, visit



The ACAAI is a professional medical organization of more than 6,000 allergists-immunologists and allied health professionals, headquartered in Arlington Heights, Ill. The College fosters a culture of collaboration and congeniality in which its members work together and with others toward the common goals of patient care, education, advocacy and research. ACAAI allergists are board-certified physicians trained to diagnose allergies and asthma, administer immunotherapy, and provide patients with the best treatment outcomes. For more information and to find relief, visit Join us on Facebook, Pinterest and Twitter.

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