No abstract

Reports of immune reactions of both the immediate and delayed types due to cutaneous or systemic exposure to copper have been reviewed, in the endeavor to draw a comprehensive profile of the immunogenic potential of that metal and its compounds. The metal's immunotoxic potential is also briefly reviewed. In principle, as noted for other transition metals, the electropositive copper ion is potentially immunogenic due to its ability to diffuse through biological membranes to form complexes in contact with tissue protein. Based on predictive guinea pig test and the local lymph node assay (LLNA), copper has a low sensitization potential. Reports of immune reactions to copper include immunologic contact urticaria (ICU), allergic contact dermatitis (ACD), systemic allergic reactions (SAR) and contact stomatitis (STO), but considering the widespread use of copper IUDs and the importance of copper in coinage, items of personal adornment and industry, unambiguous reports of sensitization to the metal are extremely rare, and even fewer are the cases, which appear clinically relevant. Reports of immune reactions to copper mainly describe systemic exposure from intrauterine devices and prosthetic materials in dentistry, implicitly excluding induction of the hypersensitivity from contact with the skin as a risk factor. We provide a diagnostic algorithm that might clarify the frequency of copper hypersensitivity.

No abstract

As one step in defining the clinical relevance of exposure to an allergen identified with patch testing, use tests (provocative use test (PUT), and repeated open application test (ROAT)) have been used. In 1 / 2 of the cases of seemingly reliable patch tests, use tests are negative, suggesting that the patient's biologic threshold of response had not been reached with open application dosing. Dramatic differences exist in regional skin reactivity and percutaneous penetration. Negative results of use tests on normal skin may become positive on diseased skin. To refine this assay further, more controlled observations and analysis of reaction differences between normal and damaged skin, and among regional anatomic sites might be performed. In addition, we require a standardized measurement for the results. Use testing has significant potential in refinement of the evidence-based diagnosis of clinical relevance. However, for general validation, we should fill the deficiencies described above.

Certain metals, and many metal-based compounds, are inherently toxic, and their presence in occupational and environmental settings raises appropriate questions concerning human exposure. Contact of these materials with the skin represents an important route of exposure, which is not well characterized. The purpose of this review, therefore, is to assemble the available, useful information pertinent to risk assessment following dermal contact. Specifically, we summarize here: (1) data relevant to the qualitative and (where possible) quantitative evaluation of metal compound permeation through the skin; (2) the role of each metal in metabolism, particularly with respect to the skin, and the potentially toxic effects that may result from dermal contact; and (3) the immunological characteristics (including allergenicity) of the metals and their derivatives. In total, information on 31 metals has been reviewed. It is clear that many diverse factors determine the ability of metal-based species to permeate biological membranes, not all of which have been fully defined. Therefore, considerably more experimentation, targeted at the development of high-quality transport data, will be required before the specification of practically useful structure-activity relationships are possible.