Environmental factors are recognized as a cause of the increasing frequency of allergic and autoimmune diseases. In addition to external pollutants, metal ions released from dental restorations or from other body implants might trigger inflammation in susceptible subjects. In humans, genes governing metal-induced inflammation and autoimmunity are not yet known. In clinical praxis, metal-sensitive patients will present various symptoms ranging from oral mucosal changes and skin disease to excessive fatigue and autoimmune diseases. Since genetic markers of genetic susceptibility in man are not known, one has to rely on the phenototypic markers. Such biomarkers might be certain detoxification enzymes but also the presence of metal-specific memory cells in the blood. With the increasing use of metal implants in medicine and dentistry, it is important to have a proper tool for the diagnosis of metal allergy in susceptible subjects. After nickel, gold is now the second most common sensitizer. In addition to patch test, an in vitro blood test, an optimized commercially available lymphocyte transformation test (MELISA) is discussed. Both tests were used for the diagnosis of metal allergy in a selected group of 15 patients who suffered from clinical metal sensitivity in addition to other health problems. The concordance of the two tests was good but MELISA detected more metal allergies than patch test. The removal of incompatible dental material (RID) resulted in long-term health improvement in the majority of patients. We postulate that in vivo, metal ions activate T-cells, initiating systemic inflammation, which, through cytokines, affects the brain and hypothalamus-pituitary-adrenal axis. We postulate that in vivo metal ions will activate T-cells starting systemic inflammation which, through cytokines affect the brain and hypothalamus-pituitary-adrenal (HPA) axis. The treatment and rehabilitation of metal sensitive patients is based on a firm understanding and recognition of individual susceptibility. RID has to be done done with extreme caution and according to standard working protocol. If performed properly, this treatment can result in decreased systemic inflammation and improved health in sensitized patients.