Effective use of antibiotics starts with a complete allergy history

Effective antibiotic use starts with allergy history

This week is Antibiotic Awareness Week, a week focused on using antibiotics appropriately to provide the best clinical outcomes and avoid antibiotic resistance.

As physicians who care for patients with antibiotic resistant infections and those with antibiotic allergies, we know that there are real clinical advantages to being able to use “narrow” beta-lactam antibiotics such as amoxicillin. In fact, for many diagnoses, patients have better outcomes when they are treated with beta-lactam antibiotics that are targeted to their specific bacteria. Furthermore, use of these antibiotics helps avoid the development of multi-drug resistant bacteria. Fortunately there are still many pediatric infections, such as streptococcal pharyngitis or community-acquired pneumonia, for which penicillin-type drugs are quite effective.

What happens, though, when patients have an allergy to these antibiotics? Penicillin is the most common drug allergy, reported in 10 percent of patients. However, 90 percent of patients who undergo drug allergy testing do not have a confirmed penicillin allergy and could safely be treated with penicillins (e.g. amoxicillin) and related beta-lactam antibiotics. Even in those with true allergy, 50 percent of patients will lose sensitivity after five years and 80 percent will lose sensitivity after 10 years.

The label of penicillin allergy comes with significant burden and is important to address with patients. Patients with penicillin allergy are treated with alternate antibiotics and have increased incidence of C. difficile and resistant bacteria, increased outpatient prescription drug costs, and in some situations, worse clinical outcomes.

One of the first things we can do as prescribers to address this is to document a complete and accurate allergy history. We don’t always do a great job with this. Allergies are documented incompletely in up to 50 percent of inpatients. We can do better. The following components are included in a complete and accurate allergy history:

  1. Medication
  2. Reaction symptoms
  3. Timing of the reaction: how long ago and at what time point during treatment.
  4. How was the reaction managed?
  5. What was the outcome?

Prescribers can also consider evaluation for penicillin allergy by an allergist/immunologist. Penicillin skin testing and oral challenge is safe and effective in the pediatric and adult populations. Boston Children’s Hospital has a newly created Penicillin Allergy Evaluation Clinic through the Division of Allergy and Immunology.

Email our Penicillin Allergy Evaluation Clinic.

About our experts: 


Kelly Flett, MD, MMSc, is an attending physician in Pediatric Infectious Diseases at Boston Children’s Hospital and the medical director of Boston Children’s Antimicrobial Stewardship Program.




Brittany Esty headshotBrittany Esty, MD, MPH, is an attending physician in Immunology at Boston Children’s Hospital and an instructor in pediatrics at Harvard Medical School.