An allergy is a serious thing. If you are allergic to a medication, typically that means one of two things:

1- You break out in hives, of varying severity, with varying degrees of itching. Hives are self-limited and can be readily treated with oral or IV Benadryl. 


2- You develop difficulty breathing with swelling of the throat and other symptoms can develop including complete circulatory collapse, also called anaphylaxis. 

Unless you demonstrate one of the above constellations of symptoms, you do not have a true "allergy." What you may have instead is called a side effect. While side effects can be unpleasant, they are not life-threatening. To consider penicillin an allergy, you limit the kinds of medications you may receive during an illness. This is no small matter. Check with your doctor before labeling yourself as having an allerkgy. Make sure that you are clear on the symptoms you have experienced. 


Excerpt from AMA Daily Email:  

Studies: Most people who think they are allergic to penicillin are not.

NBC Nightly News (11/8, story 8, 1:50, Williams) reported that “the nation’s top allergists are saying most of those” who believe they are allergic to penicillin are not.

        On its website, NBC News (11/7, Silverman) reported that in one study presented at the at the American College of Allergy, Asthma and Immunology meeting, investigators “tested 384 people who said they were allergic to penicillin. “

        ABC News (11/8) reported on its website that the investigators “found the overwhelming majority – 94 percent – of test subjects showed no allergy to penicillin.”

        HealthDay (11/8, Preidt) reported that “in the second study,” also presented at the ACAAI meeting, “penicillin skin testing was performed on 38 people who believed they were allergic to the antibiotic, and all of them tested negative for such an allergy.” Also covering the story are Medical Daily (11/10), and the Syracuse (NY) Post-Standard (11/8, Canedo).

        Survey: Many physicians may have misconceptions about allergies. HealthDay (11/8, Norton) reported that research presented at the American College of Allergy, Asthma and Immunology’s annual meeting suggests that “many primary care doctors may not be up to speed on the causes and best treatments for allergies.” Investigators who surveyed more than “400 internists and pediatricians...found that misconceptions about allergies were fairly common – particularly when it came to food allergies.” Among other things, the survey found that “one-third of all doctors, and half of internists, did not know” that “the go-to treatment for a person who develops hives and vomiting after eating a known food allergen” is an epinephrine injection.