S. Shahzad Mustafa
Very few children with reported penicillin allergy have a reaction when tested with a graded challenge, according to research presented at the American Academy of Allergy, Asthma and Immunology Annual Scientific Meeting. The findings add to growing evidence that penicillin allergy is overreported.
“Our study goes on to show that in patients at low risk for penicillin allergy — namely those with a history of rash only — a medically supervised, graded drug challenge was effective in de-labeling penicillin allergy, took less time and appeared to be less costly than penicillin skin testing (PST),” S. Shahzad Mustafa, MD, FAAAAI, lead physician in the department of allergy and clinical immunology at Rochester Regional Health and clinical associate professor of medicine at the University of Rochester School of Medicine and Dentistry, told Infectious Diseases in Children.
Mustafa and colleagues conducted a prospective, randomized trial to evaluate PST followed by an amoxicillin challenge compared with a two-step graded challenge to amoxicillin without PST. Patients aged older than 5 years with only cutaneous or unknown reactions to penicillin were randomly assigned 1:1 to receive either PST or graded challenges. An unknown reaction was considered an event occurring more than 1 year ago for children aged 5 to 17 years and more than 10 years ago for patients aged 18 years and older. Children aged younger than 5 years also received graded challenges. If patients in this age group had a history of extracutaneous reactions, they underwent further PST.
Mustafa and colleagues monitored patients for 30 minutes after administering amoxicillin.
Of the patients presenting to the clinic, 15.8% reported a penicillin allergy (n = 256), and 139 of these patients consented to further evaluation. Direct challenges were given to 13 patients aged younger than 5 years, and all produced negative results. Ten patients who had angioedema, extracutaneous symptoms or both also received PST. Only one patient was positive for the allergy.
Most patients aged older than 5 years who were randomly assigned to receive PST received negative results (87.5%). Of the 70 patients with negative results, all had negative amoxicillin challenges. Of the patients who were randomly assigned to receive a graded challenge, 96.2% had negative results.
According to the researchers, the average amount of time spent on PST was 72.7 minutes. Graded challenges took an average of 66.7 minutes.
“Pediatricians and allergists should be aware of the impact of penicillin allergy on health care and pursue testing to either confirm or, more likely, to de-label patients with reported penicillin allergy,” Mustafa said. “An evaluation takes roughly 70 minutes and can be done with penicillin skin testing or possibly a graded drug challenge. Both approaches appear safe and effective in evaluating low-risk individuals with penicillin allergy.” – by Katherine Bortz
Reference: Mustafa SS, et al. Preliminary results comparing outpatient oral graded challenges to skill testing. Presented at: American Academy of Allergy, Asthma and Immunology Annual Scientific Meeting; Feb. 22-25, 2019; San Francisco.
Disclosure: Mustafa reports no relevant financial disclosures.