People with a penicillin allergy in their medical records do not receive penicillins (or often their relatives, cephalosporins) when they have infections. Instead, prescribed antibiotics can be broader spectrum, less effective, and / or more toxic.
Alternatives to penicillin may be less effective or more toxic
A recent national study in over 100 US hospitals with nearly 11,000 patients showed that if you have a reported penicillin allergy, you are five times more likely to be prescribed clindamycin than if you did not. this label. Clindamycin is an antibiotic that is strongly associated with life-threatening effects Clostridioides difficile (C. diff) gastrointestinal infection. A study using full UK data recently confirmed that people with allergies to penicillin have an increased risk of C. diff. 69%.
When patients undergo surgery, a penicillin limb (cefazolin) is often used to prevent infection at the surgical site. However, according to this study, in patients labeled with a penicillin allergy, cefazolin is routinely avoided in place of a less effective substitute, resulting in a 50% higher risk of operating site infections for people documented allergic to penicillin.
Confirming or ruling out penicillin allergy by penicillin allergy testing could justify the risks, or potentially avoid, by allowing beta-lactams (the class of drugs that include penicillins and cephalosporins) to prescribe beta-lactams when they are needed. Even some patients with a severe history of penicillin allergy can safely take penicillins again, as the penicillin allergy often does not persist for life. In total, about 95% of people tested for penicillin allergy in the United States are not allergic.
What are penicillin allergy tests?
Penicillin allergy testing often begins with a history of allergy. In order to know if the test is appropriate, the clinician needs to know certain details of the reaction, such as: When did this happen? What were the symptoms? How were you treated?
If necessary, the next step may be the penicillin skin test. This test involves pricking the skin and introducing a small amount of allergen. Anyone with a positive skin test for penicillin – there is usually itching, redness, and swelling at the test site – is allergic and should avoid penicillin.
People who have no reaction to the skin test may experience the challenge of amoxicillin. In this test, the clinician gives the person amoxicillin (a type of penicillin) and watches for signs and symptoms of an allergic reaction for at least an hour.
Allergists regularly perform penicillin allergy tests. Other types of doctors, nurses, nurse practitioners, and even pharmacists can be trained to do skin tests for penicillin allergy in the United States. The amoxicillin challenge test can also be done by a variety of health care providers, provided they are comfortable diagnosing and treating allergic reactions.
New clinical tools may help assess the likelihood of a true penicillin allergy
There are a growing number of clinical tools that can help your primary care physician or other non-allergic healthcare professional assess whether you have a true penicillin allergy.
The first tool is a risk stratification diagram, published in JAMA and approved by several professional associations. The review encourages the prescription of an amoxicillin challenge in low risk patients. Patients are classified as low risk if their reactions occurred more than 10 years ago and: were isolated and mildly allergic (gastrointestinal symptoms, headache); itching without a rash; and did not include allergic symptoms such as hives, swelling, wheezing, shortness of breath, or chest tightness. the JAMA The review recommends that medium-risk and high-risk patients, including those who have experienced one or more allergic symptoms or an anaphylactic reaction, have a skin test before completing an amoxicillin test.
Another recently developed tool, called PEN-FAST, can be used by all types of healthcare providers to help decide if it is safe to give you penicillin, and potentially remove your allergy label (“you decay”). The tool uses your allergy history to determine a risk similar to JAMA expert guide.
|PEN||PENallergy to icillin reported by the patient|
|F||Ffive years younger since the reaction||2 points|
|A||Anaphylaxis or Angioedema|
SEversing an adverse skin reaction
|T||Ttreatment required for the reaction||1 point|
PEN-FAST stands for PENallergy to icillin reported by the patient, Ffive years or less since the reaction, Anaphylaxis or Angioedema, Sany side effects on the skin, Ttreatment required for the reaction. You receive a score based on your answers to these four criteria, which reflects the likelihood that you have a true penicillin allergy.
While you are probably familiar with the “F” and “T” parts of FAST – when this happened and if you were treated – ratings for “A” and “S” reactions should be discussed with your doctor. Anaphylaxis is a body-wide allergic reaction, and angioedema is severe swelling under the skin. In addition to severe side effects on the skin, these are serious and potentially fatal reactions.
Patients who are able to say “no” to all four PEN-FAST criteria (0 points) have a very low risk of a true penicillin allergy. A total score less than 3 indicates a low risk of penicillin allergy. These two groups of patients would be likely to tolerate challenge to amoxicillin. Of course, you and your doctor should be prepared for an allergic reaction before ingesting any medicine to which there is a possible allergy.
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