Contact allergy to cardiac devices is not common but should be considered when there is concern for infection, a history of device extraction, a history of erythema at the implant site or negative culture results, according to a research letter.
Researchers from Duke University School of Medicine and Aurora St. Luke’s Medical Center in Milwaukee conducted a retrospective study of 11 patients who underwent 15 sessions of cardiac implant patch testing. Mean patient age was 58.4 years, and 27% of patients were women.
Devices were extracted in eight of the 11 patients. The duration of device implantation before extraction ranged from 1 to 77 months if the extraction occurred before patch testing and from 1 to 11 months if the extraction occurred after patch testing.
Positive patch test reactions were found in six patients, and four of these reactions included metals. Reactions to rubber accelerators, lidocaine, silicone and a device-related dexamethasone plug also tested positive.
Eight patients had a history of erythema at the implant site.
The device was extracted in six patients before patch testing and in one patient 4 months after patch testing. Five out of seven available cultures had negative results.
Except for one case, relevant allergens were avoided during reimplantation.
As of September 2017, one patient had died, while the remaining patients’ devices were functioning.
“[O]f the five patients with negative patch tests, three patients kept their devices, which demonstrated that the negative patch test results had important diagnostic value,” the researchers wrote. “The remaining patients had their devices extracted prior to testing, and reimplantation was not indicated.” – by Abigail Sutton
Disclosures: The authors report no relevant financial disclosures.