Patch testers' opinions regarding diagnostic criteria for metal hypersensitivity reactions to metallic implants.

BACKGROUND: Metal hypersensitivity reactions to implanted devices remain a challenging and controversial topic. Diagnostic criteria and methods are not well delineated.

OBJECTIVE: Diagnostic criteria for hypersensitivity reactions after metallic device implantation are evaluated in this study by a multinational group of patch testers using Thyssen's previously published criteria.

METHODS: A total of 119 dermatologists at the 2012 European Contact Dermatitis Society and 2013 American Contact Dermatitis Society meetings answered a survey regarding their opinions on topics relating to metal hypersensitivity.

CONCLUSIONS: Four major and 5 minor diagnostic criteria emerged. Approximately 80% of respondents found the following criteria useful (major criteria): chronic dermatitis beginning weeks to months after metallic implantation, eruption overlying the metal implant, positive patch test to a metal component of the implant, and complete clearing after removal of the potentially allergenic implant. Minor criteria (<61% of respondents) were as follows: systemic allergic dermatitis reaction, therapy-resistant dermatitis, morphology consistent with dermatitis, histology consistent with allergic contact dermatitis, and a positive in vitro test to metals (eg, lymphocyte transformation test). In the challenging situation such as a symptomatic or failing orthopedic device, applying these 4 major criteria and the 5 supportive minor criteria may be useful for guiding decision making.