[Metal implant allergy update].

Intolerance reactions to metal implants may also be caused by metal allergy. A differential diagnostic workup must be performed based on the complaints of the patient. For patch testing the standard series with its nickel, cobalt, chromium preparations is used. There is no consensus regarding implant metal test series or, for example, bone cement test series; however, progress is being made. The combination of several diagnostic tools including histology is useful. The lymphocyte transformation test (LTT) must be performed by experienced laboratories and results must be carefully evaluated. New insights into pathomechanisms of intolerance reactions to metal implants and identification of potential biomarkers are expected.