Millions of people mistakenly think they’re allergic to penicillin
Penicillin is one of the best antibiotics against potentially lethal infections, but many people mistakenly think they are allergic. Here’s a look at the symptoms of a true allergy and other details about penicillin.
September 28th marked the 95th anniversary of the discovery of penicillin. As one of the best antibiotics against potentially lethal infections, it is unfortunate that millions of people mistakenly think they have a penicillin allergy.
Approximately 10% of all US patients report having an allergic reaction to a penicillin. However, many patients who report penicillin allergies do not have true IgE-mediated reactions. When evaluated, less than 1% of the population is truly allergic to penicillin. Similarly, according to the Royal Pharmaceutical Society, although 6% of people in the UK have a penicillin allergy label on their medical record, 90% of those patients were found not to have an allergy when fully assessed.
Even patients who had a true penicillin allergy in the past may lose that allergy over their lifetime. Studies show that approximately 80% of patients with IgE-mediated penicillin allergy lose their sensitivity after 10 years.
Cost of a mislabeled penicillin allergy
Being labeled allergic to penicillin is associated with a higher mortality rate of an extra six deaths per 1,000 patients in the year following treatment for infection. In addition, broad-spectrum antibiotics are often used as an alternative to penicillin’s. The use of broad-spectrum antibiotics in patients labeled “penicillin-allergic” is associated with higher health-care costs, an increased risk for antibiotic resistance, and suboptimal antibiotic therapy.
For example, a recent study of 838 patients receiving dental implants showed that those who had a “penicillin allergy” and were given another antibiotic during implant therapy had a failure rate more than twice that of patients without an allergy and given penicillin. An explanation of this increased failure rate is that penicillin and its derivatives are a superior choice for antibiotic coverage during dental implant procedures.
Why do patients think they have penicillin allergies?
Many people believe they are allergic to penicillin for a variety of reasons such as:
1. Common side effects of antibiotics: such as nausea, gastrointestinal upset, cramps, bloating, headache, dizziness, and/or diarrhea are often confused with allergic reactions.
2. Symptoms of the infection being treated: A rash, for example, could be considered an allergic reaction and reported as such.
3. Allergy reported in the past: An allergy during childhood may disappear, but the perception of an allergy remains. Parents told the patient they were allergic: Patients may have been told they were allergic to penicillin without proper testing.
What are the symptoms of a true penicillin allergy?
1. A true penicillin allergy is IgE-mediated and includes:
· Adverse reactions: reactions that occur immediately or usually within one hour of taking an antibiotic
· Hives: multiple pink or red raised areas of skin that are intensely itchy
· Angioedema: localized edema without hives affecting the abdomen, face, extremities, genitalia, oropharynx, or larynx
2. Breathing issues: wheezing and shortness of breath
3. Anaphylaxis: hypersensitivity (as to foreign proteins or drugs) resulting from sensitization following prior contact with the causative agent
What are the signs and symptoms of anaphylaxis?
Anaphylaxis is an acute allergic reaction that includes at least two of the following systems:
· Skin: hives, flushing, itching, and/or angioedema
· Respiratory: cough, nasal congestion, shortness of breath, chest tightness, wheeze, sensation of throat closure or choking, and/or change in voice quality (laryngeal edema)
· Cardiovascular: hypotension, faintness, tachycardia (or less commonly, bradycardia), tunnel vision, chest pain, sense of impending doom, and/or loss of consciousness
· Gastrointestinal: nausea, vomiting, abdominal cramping, and diarrhea
This is a serious issue that can have disastrous and deadly results in a medical/ dental environment if you are truly allergic as this is the go to antibiotic for any infection. If you think you are then you should be evaluated by an allergist who can tell you if you are truly allergic.
If you are allergic to Penicillin it is important that you know and have a way of alerting medical personnel to this fact such as a card or bracelet. This could be helpful in a situation where you may not be able to respond to medical personnel.
Until Next time: Stay Safe, Stay Healthy and be Careful out in the World.
James A Vito, D.M.D.