Patch Testing in Solid Organ Transplant Recipients: Experience From a Tertiary Medical Center Over 13 Years (2010-2022)

Background: It is generally recommended that patients not be on immunosuppressive medications for patch testing, as these medications may suppress delayed-type hypersensitivity and lead to false negative results. There is a paucity of literature describing organ transplant recipients who underwent patch testing. Objective: The aim of this study is to examine patch testing results in solid organ transplant recipients over a 13-year period at our institution. Methods: We performed a retrospective analysis of patch test data from adult transplant recipients at our institution. Transplant patients who underwent patch testing were identified from a clinical patch test database, and a chart review was conducted. Results: Eighteen patients were included in the study. Patients had received kidney, liver, or heart transplants. Seven patients (38.9%) had at least one positive reaction. The highest reaction rates were seen with methylisothiazolinone (12.5%), methyldibromo glutaronitrile (12.5%), and benzalkonium chloride (10.0%). Limitations included small sample size, data from a tertiary referral center, and retrospective analysis. Conclusions: Liver and kidney transplant recipients displayed allergic reactions during patch testing. Patients may benefit from patch testing even if receiving immunosuppressive therapy, but some reactions may be falsely negative because of immunosuppression.