Can EBV-Related Penicillin Rashes Signal Long-Term Allergy?

TOPLINE:

Nearly half of the adolescents and adults who developed rashes from penicillin during an Epstein-Barr virus (EBV) infection showed evidence of persistent drug hypersensitivity.

METHODOLOGY:

• Patients with EBV infection sometimes receive antibiotics because the viral infection can mimic bacterial ones. A characteristic maculopapular rash — often considered self-limiting — can develop in this circumstance.
• Researchers analyzed data from 15 patients who developed a rash after taking penicillin during an EBV infection and later underwent drug allergy testing between 2012 and 2023 (median age at the time of the EBV-related rash, 18.5 years; 86.7% women).
• Drug allergy skin tests included intradermal tests with readings at 48 hours and patch tests with readings at 48 and 72 hours. The drugs tested were amoxicillin, amoxicillin/clavulanate, ampicillin, penicillin G, and cefuroxime.

TAKEAWAY:

• Skin tests showed persistent sensitization in 46.7% of patients; five patients tested positive on both intradermal and patch tests.
• Of four patients who had been reexposed to penicillins before their allergy evaluation, three had recurrent drug hypersensitivity reactions, including one case of acute generalized exanthematous pustulosis.
• The median time to diagnostic evaluation after the initial EBV-related rash was 16 months (interquartile range, 4.3-111).
• Overall, 66.7% of patients experienced a rash lasting 7 days or longer.

IN PRACTICE:

“Our findings underscore the importance of avoiding premature and uncritical labeling of patients as penicillin allergic or not, solely based on a rash occurring during EBV infection,” the authors of the study wrote.

SOURCE:

Lukas Joerg, MD, with Bern University Hospital in Bern, Switzerland, was the corresponding author of the study, which was published online on August 13 in International Archives of Allergy and Immunology.

LIMITATIONS:

The study was limited by its retrospective design, relatively small sample size, and lack of drug provocation testing in patients with negative skin tests. The researchers cautioned that negative skin test results may not exclude allergy, and some patients testing negative may still experience hypersensitivity upon rechallenge. Additionally, high rates of nonparticipation or loss to follow-up may have biased the findings.

DISCLOSURES:

The authors declared having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.