Most dermatologists are familiar with patch testing, but expanded testing beyond standard trays is not ubiquitous. Patients with metal implants (orthopedic, dental, or cardiac devices) referred to dermatologists for patch testing present a unique challenge an important practice gap. How should we manage these patients? Who benefits from testing? What, if any, impact does patch testing have on implant selection or management?
Whether seeing the patient preoperatively to determine what metals the patient is allergic to or postoperatively to help manage issues of joint failure or device complications, the dermatologist must set realistic expectations for the patient and referring physician about what information will be obtained through patch testing. For the patient undergoing testing prior to implant selection, the dermatologist must emphasize that the patch test detects current allergy but is not indicative of future allergy. In addition, limitations must be discussed. The patch test is a cutaneous test that does not recreate the environment in which the metal resides. Therefore, the testing might not recreate or elicit the same response as that of a metal within a joint space, for example. Coordinating the patch test procedure with a surgeon's timeline is yet another challenge.