[Amalgam allergy--diagnosis and consequences]

Allergy to dental amalgam is rare--in contrast to Press reports and public opinion. Whereas sensitivity to one or more mercury salts is quite frequently detected in the patch test, it is seldom of clinical relevance. In this report we define the limited indications for performing an allergy test, describe the exact test criteria and delineate the consequences of a positive test result. A critical appraisal of the result is essential in order to avoid unnecessary procedures which are expensive and far from being effective, may even be potentially dangerous.