Are you sure you have a penicillin allergy?
Posted: 30th March 2018 | Posted by Costa
Are you sure you have a penicillin allergy?
Penicillin is the most reported drug allergy in the world. Approximately 10% of the UK population report having a penicillin allergy. Yet it’s estimated that only around 20% of those reporting are truly allergic. So that means it might be closer to 2% of the population. But why do so many people think they are allergic to penicillin when they are not?
Symptoms
Sometimes, perceived allergy symptoms coincide with the use of penicillin. But, they may be due to another cause. For example, some bacterial infections cause rashes. You may believe the cause of the rash is the penicillin rather than the infection. Or, you may have misinterpreted some of the common or less common side effects of penicillin as an allergic reaction. All drugs have possible side effects. Many of them resemble allergy symptoms, but they are not.
For those who are genuinely allergic to penicillin, reactions can occur immediately after exposure. Their symptoms will be those of an immunoglobulin E allergic reaction. Symptoms range from rashes and hives to breathing difficulties and anaphylactic shock. This can be fatal, so it’s still very important to take penicillin allergies seriously. If you think you may have a penicillin allergy, it’s best to seek the diagnosis of professionals to be certain of the cause. Having a false diagnosis, or assuming it’s an allergy, can have adverse effects on you in the long term.
Be vigilant
One of these adverse effects is related to the worrying global issue of antibiotic resistance. 50,000 people die every year from antimicrobial-resistant infections. Some scientists have described it as a bigger threat to humanity than climate change. Skipping penicillin for alternatives is not contributing to microbial resistance as much as other poor practices, like using antibiotics in agriculture or misprescription. But, it does widen the varieties of drugs we are exposing to bacteria. So, not only are microbes becoming resistant to penicillin, they are becoming resistant to the backup options we have as well.
People who are allergic to penicillin cannot avoid this, and proper use of antibiotics is unlikely to contribute to antibiotic resistance. But, the large number of people who use alternatives due to false allergy diagnosis, increases the risk of misuse and therefore, resistance. Also, penicillin alternatives are often more costly, putting greater strain on an already overwhelmed NHS, and they are not always as effective as penicillin in some conditions.
Get it right
This is why ensuring your reaction to penicillin results from an allergy is important. In the long run, it could be worth putting up with mild, non-allergenic symptoms for the greater good. If your symptoms are more severe, it’s best to avoid penicillin in favour of alternatives to protect your health. But, getting a proper diagnosis is still important as it could affect your treatment in hospital.
In some situations when drug allergy is confirmed and there are no alternative options for use of other medications, patients could undergo desensitisation therapy in a hospital setting that will allow one-time use of the drug.
It’s very important to be sure if the historic rash was indeed a sign of severe allergy or was due to something else, in order to have the best options available to you in hospital.
If you want to get tested for a penicillin allergy, or another allergy you think you may be suffering from, book an appointment with us today. If you plan to claim private insurance please get a referral from your GP.

