Contact allergy to gold as a model for clinical-experimental research.

The high frequency of contact allergy to gold in patients with dermatitis was established after exhaustive skin testing, determining the right test agent, the best concentration, and repeated test readings. Metallic gold in contact with skin is slowly ionized, permitting absorption and haptenisation. Contact allergy to gold is statistically correlated to the presence of dental gold. But in many case reports it has also been attributed to wearing gold jewellery, albeit not statistically demonstrated. Epicutaneous testing with gold salts increases the blood gold level, and by intramuscular injection systemic contact dermatitis is provoked in an allergic individual. In coronary heart disease, gold-coated intravascular stents have been shown to be correlated to contact allergy and even to an increased risk of restenosis. Gold is far from inert.