75% of people allergic to penicillin are not allergic, new study finds

If you have been diagnosed with a penicillin allergy for many years, this may not be true. And this is what 75% of patients with allergies to beta-lactam antibiotics or penicillins are false positives. This is evidenced by a study conducted by a clinical group led by Gustavo Molina, a specialist in the allergology service at the University Hospital of Bellvitge (HUB), which analyzed 249 cases of allergies to these drugs in people. Of the total number of patients examined, in 186 cases (74.3% of the total) the label was removed after allergy testing. In an analysis confirming the results of similar studies, experts Allergology, clinical pharmacology and pharmacy of public hospitals ICS. The mean age of patients in the multicenter study was 55.8 years.

There are many reasons for this, as Molina explains to CuídatePlus. ““We believe this is a multifactorial problem.”. Among the main reasons are: “insufficient training of specialists assessing reactions at an acute moment, inaccurate marking systempatient recall bias, lack of standardization in labeling, and The trend, many years ago, was to avoid beta-lactam antibiotics when allergies were suspected. instead of sending them for specialized research,” he explains in detail. Nowadays, when faced with these labels, the patient is usually referred to a specialist for evaluation.

What can happen if you think you have an allergy but you don’t?

“Falsely labeling allergies to penicillins and other beta-lactams is not a minor problem, it is a public and personal health problem,” says Gustavo Molina. Overdiagnosis of drug allergies has several serious consequences, such as: use of more harmful, more expensive and less effective therapeutic alternatives., increased surgical wound infections or increased hospitalization time. Besides, It also contributes to the rise in antibiotic resistance, in the global context of the rise in multidrug-resistant bacteria, which poses a growing threat to global public health.

The presence of a “false allergy” to this particular drug is important because of its widespread use in everyday clinical practice. And that’s what Beta-lactam antibiotics “are used to treat very common infectious pathologies.” For example, “they are commonly used for respiratory, urinary, skin infections and others,” says the expert.

So what can be done? As Molina explains, “Once a patient has a penicillin allergy label, The episode must first be assessed and whether there is a regulated study by allergy specialists to support this.”

For those patients who have a known penicillin allergy and have never been studied, “allergy testing should be considered on an individual basis.”

What will the verification test consist of?

The study of penicillin allergy, the expert describes, “consists, first of all, of at an appointment with a specialistallergist in this case”

During this visit, in accordance with the patient’s medical history and taking into account his personal medical situation,The risk of a true allergy will be assessed before any other additional testing is performed. Adequate preliminary assessment is the basis of diagnosis and patient safety.” No additional tests are carried out “without a visit in which these aspects are taken into account.”

Subsequently, according to the data collected in the anamnesis, skin testing may be considered

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These tests”consist of applying small drops of beta-lactam antibiotics to the forearm., where a small puncture is subsequently made so that the antibiotic comes into contact with the epidermal cells. In case of a negative result, a deeper puncture is considered to contact the drug with the cells of the lower layers of the epidermis.” The reading is taken after 20 minutes and assessed as positive or negative.

In some cases, analytical determination can be made “To help diagnose or rule out penicillin allergy.” This is a more limited test because it can only be detected for a few antibiotics in this family.

According to the results of the above tests, The final step for evaluation is the controlled exposure test.

This test “consists of controlled exposure to the penicillin suspected of causing the initial reaction, or an alternative if previous studies indicate a clear possibility of penicillin alone.”

This latter procedure “poses the greatest risk to the patient when Hypersensitivity reactions may occur that mimic the initial reactions or may be milder or more severe.. For this reason, they should not be taken lightly.”

Thus, he concludes, “they must be carried out in a safe environment and by personnel trained to identify and treat these reactions, as they have the potential to put lives at risk.”