Penicillin Skin Testing, Challenge, and Desensitization in Pregnancy: A Systematic Review

This study sought to evaluate available evidence of the safety of penicillin skin testing (PST), challenge, and desensitization in pregnancy, with efforts to improve perinatal care for patients with a penicillin allergy history and mitigate the negative sequelae of unverified penicillin allergy labels.

A systematic review of studies was conducted using Cochrane Library, Medline, EMBASE, and International Pharmaceutical Abstracts. Included were peer-reviewed studies without date restrictions, published in English or French, relating to PST, challenge, or desensitization in pregnancy. Editorials, opinion pieces, and letters were excluded. Review authors independently screened citations and full-text articles, extracted data, and conducted quality assessment. Given the heterogeneity of study designs, a narrative synthesis was conducted.

The search identified 1195 references, of which 18 studies met inclusion criteria. In total there were 231 patients with varying histories of penicillin allergy, the majority requiring treatment for syphilis or group B streptococcal (GBS) disease during pregnancy. Of the 203 participants who underwent PST, 83.7% had negative test results. Allergy-related reactions were rare in PST (1.5%) and challenge (0%), and although these reactions were more common in desensitization (19.7%), most were benign. Among the 231 cases, only one adverse pregnancy outcome was reported (0.4%).

This review demonstrates that the known prevalence of true penicillin allergy extends to pregnant women. PST and desensitization can be safely applied during pregnancy and are tools that should be used more frequently. Further data on the safety of challenge during pregnancy are recommended.