It is being
said by the CDC that people who thought they were allergic to penicillin might
not actually be. In the US about 10% of patients state that they have an
allergy to penicillin, where in actuality less than 1% of the population has a
true allergy to the drug. First lets talk about what actually causes a person
to have an allergy. A penicillin allergy is actually caused by IgE-mediated
reactions to the reactive ingredients in penicillin called antigen determinants.
IgE-mediated stands for immunoglobulin E-mediated. When a person is allergic to penicillin their
immune system reacts to the drug as if it is a harmful viral or bacterial
infection. When the allergy develops the person’s immune system is then sensitive
to penicillin.
So how
could the people who thought they were allergic to penicillin not actually be
allergic? One way is that when the person was initially diagnosed as being
allergic to penicillin they actually just had similar symptoms as the actual
allergy. Or that someone who was allergic simply lost their allergy over time.
About 80% of people who had a true penicillin allergy lose their sensitivity to
the drug about 10 years after the reaction. So why is this important? This is
important because it can reduce the unnecessary use of broad-spectrum
antibiotics that people who are allergic to penicillin use. For the people who
have thought they were allergic to penicillin they can take a penicillin skin
test as well as an oral penicillin-class challenge to test if they are allergic.
If both of these are negative then a penicillin allergy can be ruled out.
References
Jenea-
ReplyDeletePersonally, I have never taken penicillin so I don’t know if I am allergic to it or not (although, I have a friend who is, so I am going to make him read your blog!) However, I have had a mild allergic reaction to Bactrim. Your post makes me wonder if the reaction I had was an immune response to the drug as a harmful substance, similar to a penicillin allergy. I also wonder about the loss of sensitivity in individuals with a true allergy. It would be interesting to learn about the mechanism of this desensitization. In addition, I wonder if the desensitization associated with the loss of allergy has any impact on the effectiveness of the antibiotic to fight bacteria in the body. Interesting topic choice!
I think it would be important for adults to get retested for their allergy. Avoiding use of broad spectrum antibiotics is a huge advantage. Using these types of antibiotics can be harmful over time since they can kill off helpful bacteria in your gut. Avoidance of these broad spectrum antibiotics would help an individuals overall health. Really interesting read and makes me wonder if this could be common for other types of antibiotic allergies, since I am allergic to the antibiotic Augmentin.
ReplyDeleteTo think that someone could be allergic to penicillin one day and then find out down the road that they aren't is very interesting. I also wonder how that could happen. Additionally, I wonder how many other allergies in general could be outgrown over time.
ReplyDeleteI can't remember the last time I knew of a person being prescribed penicillin, allergy history or not...are MDs just assuming that people are allergic, or are there issues with production that make other antibiotics more desirable?
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