You may want to test your penicillin allergy
Sir Alexander Fleming discovered penicillin in 1928. Fleming was a Scottish bacteriologist involved in the study of bacteria.
For research and diagnostic purposes, he grew Staphylococcus (a gram of positive bacterium) in Petri dishes containing a solid medium with nutrients to support the growth of bacteria.
One day, Fleming noted there were no bacteria growing in a dish that was next to a window and exposed to the elements.
He also found that a mold called penicillium was growing in the Petri dish instead of the bacteria. He rightly decided the mold penicillium somehow was preventing the growth of Staphylococcal bacteria.
Later, he proved that the mold was making a substance, which he named penicillin, that was inhibiting the growth of bacteria. For this discovery, he gained a Nobel Prize in Medicine in 1945.
In 1999, Time magazine named Fleming one of the hundred most important people of the 20th century who changed the course of history.
Are you allergic to penicillin?
Penicillin was the first antibiotic discovered by man. It led to the discovery of many more antibiotics.
It saved the lives of millions of people all over the world during war and peace.
Unfortunately, with its widespread use rose the number of people who developed allergy to it.
With this development, doctors began using costlier and often less-effective antibiotics for treating infections. This resulted in development of drug resistant bacteria such as MRSA (Methicillin Resistant Staphylococcus Aureus) which is causing havoc among both outpatients and inpatients all over the world.
It is becoming clear that something needs to be done to cut short this growing menace. Many people do not know that up to 70 percent of people who report penicillin allergy grow out of it about 10 years after experiencing a convincing penicillin allergic reaction.
Their bodies simply stop making allergic antibodies to penicillin because of penicillin avoidance.
These people unnecessarily avoid penicillins and use costlier and less-effective antibiotics for the rest of their lives! A word of caution is necessary here. Please do not take penicillins on the assumption that you might not be allergic to it any longer.
A negative penicillin allergy skin test to show that you are not allergic is necessary before you could take penicillin again!
Types of allergic reactions
Penicillin allergy is the most common reported drug allergy in the United States. It affects 1 percent to 10 percent of people receiving the drug. It affects even people without other allergic tendencies such as hay fever and asthma.
Penicillin could cause several types of allergic reactions. This ranges from minor rash to life-threatening anaphylaxis. The humoral arm (IgE antibody) of the immune system arbitrates more immediate reactions such as hives, itching, swelling of different parts of the body and anaphylactic shock.
The cellular arm of the immune system (nonIgE) arbitrates other types of reactions ranging from minor (rash) to more severe and life-threatening (Steven-Johnson Syndrome and Toxic Epidermal Necrolysis) reactions. If you have experienced any of the later reactions, then you should avoid penicillins and related medicines for the rest of your life!
Allergy skin tests to rule out IgE-mediated penicillin allergy are commercially available now. Allergy and immunology specialists offer these tests in their offices in outpatient settings.
You need to be off antihistamines and other potentially interfering medications before undergoing the test. Check with your doctor first before you stop any medications that you are taking currently.
The test involves pricking your skin with Pre-Pen (penicillin allergy testing material) and Benzylpenicillin (an injectable form of penicillin).
If the prick tests are negative for penicillin allergy, intradermal skin tests with the same reagents are carried out to be sure that you are not allergic to penicillin.
If both prick and intradermal testing for penicillin allergy are negative, then your doctor may challenge you with oral penicillin tablets and keep you in the office for some time.
The entire procedure should take no more than two to three hours to complete, and you should know by then if you could take penicillins in future or not!
Some European allergists believe that inclusion of amoxicillin (semi-synthetic penicillin) in the test improves on the diagnostic accuracy of the test.
A negative prick and intradermal skin tests using Pre-Pen and Benzylpenicillin alone can rule out penicillin allergy in 97 percent of patients.
Please visit www.prepen.com to learn more about penicillin allergy skin tests.
Natarajan Asokan, M.D., F.A.A.P. is a board-certified allergist and immunologist and a board-certified pediatrician. He can be reached at 1739 Beverly Ave., Suite 118, Kingman, AZ 86409, or (928) 681-5800.