Patients with a positive penicillin skin test will likely experience reduced sensitivity to the medication over time and should undergo repeat testing, according to research presented at the American College of Allergy, Asthma and Immunology Annual Scientific Meeting.
“Penicillin skin testing is an important diagnostic tool in the evaluation of IgE-mediated penicillin allergy,” Dayne Voelker, MD, from Mayo Clinic School of Graduate Medical Education, and colleagues wrote. “Previous research suggests that the rate of positive penicillin skin testing is falling and that previously positive penicillin skin testing turns negative overtime. Characterizing the decrease in penicillin skin testing sensitivity over time is important to determine if these antibiotics could be used in the future.”
To investigate whether penicillin sensitivity should be retested in the future, Voelker and colleagues reviewed the electronic medical records of patients who had a history of penicillin allergy and underwent penicillin skin testing.
Age at initial penicillin skin test varied widely, ranging from 2 to 82 years.
The researchers identified 385 patients with a positive penicillin skin test. Of those, only 14 were retested. These patients had initial positive results to benzyl-penicilloyl (n = 5), PCN G (n = 5), amoxicillin (n = 3) or penicilloate (n = 1). All repeat penicillin skin tests came back negative. There was a mean duration of 5.93 years from initial skin testing to repeat skin testing.
A mean of 20 and 27 years occurred from the original reaction to the first and second penicillin skin test, respectively.
“Patients with a positive penicillin skin test will likely lose sensitivity to penicillin with time,” Voelker and colleagues concluded. “Patients with a positive penicillin skin test should be re-evaluated with repeat testing in the future.” – by Alaina Tedesco
Voelker D, et al. Abstract P007. Presented at: American College of Allergy, Asthma and Immunology Annual Scientific Meeting; Nov. 15-19, 2018; Seattle.
Disclosures: Healio Internal Medicine was unable to confirm relevant financial disclosures prior to publication.