Why many people allergic to penicillin really are not (and why this confusion can be dangerous)
In the USA, for example, 10% of patients report being allergic to penicillin, and 90% of them can actually tolerate the drug.
A basic question that doctors ask before prescribing an antibiotic is if you are allergic to any drug.
Of all reported adverse reactions, penicillin allergy is the most common.
However, according to a study conducted by researchers at the Massachusetts General Hospital in Boston, United States, and published in the British Medical Journal, most patients who believe they are allergic to this antibiotic are not.
In the USA, for example, 10% of patients report being allergic to penicillin, and 90% of them can actually tolerate the drug.
This error, the researchers say, has negative consequences for health, since these patients are prescribed other broad spectrum antibiotics that are not only more expensive but can also kill good bacteria, in addition to bad ones.
After analyzing the medical records collected over six years from more than 300,000 adults in the UK, the researchers noted that people who are allergic to penicillin are 70% more likely to get methicillin- resistant Staphylococcus aureus, or MRSA , a strain of the bacterium. Staphylococcus aureus that has become resistant to several antibiotics.
They also have more risks than non-allergic patients (26% more) of suffering colon inflammation due to Clostridium difficile infection (C.diff).
These bacteria are common in the environment and can live in the intestines and on the skin without problems.
But when a patient is prescribed (for another problem) a broad-spectrum antibiotic that ends up killing good bacteria in addition to the bad ones, MRSA or C.diff multiply and can be problematic.
Where confusion comes from
According to the researchers, the problem arises from a misdiagnosis : a rash (rash on the skin of a deep red color) can be misinterpreted as an allergy, or symptoms such as headache or diarrhea can be mistakenly associated with penicillin, when they were reality caused by other factors.
It often happens that they manifest at the same time that the patient is taking antibiotics and they make this association
On the other hand, many patients who have manifested an allergic reaction to penicillin at some point in their lives, do not remain hypersensitive to this drug 10 years later.
However, the solution is simple: the problem is solved with a test , which allows an accurate diagnosis.
The most common test is done by administering a small amount of penicillin to the skin with a tiny needle.
If the injection causes a high red bump and itches, the reaction is positive.
