Patch Testing With a Large Series of Metal Allergens

Findings From More Than 1,000 Patients in One Decade at Mayo Clinic

Mark D.P. Davis; Michael Z. Wang; James A. Yiannias; James H. Keeling; Suzanne M. Connolly; Donna M. Richardson; Sara A. Farmer


Dermatitis. 2011;22(05):256-271. 

In This Article

Abstract and Introduction


Background: The standard allergen series used in patch testing contains metals that most commonly cause allergic contact dermatitis, but testing with additional metal allergens is warranted for select patients.
Objective: To report our experience with patch testing of metals.
Methods: We retrospectively analyzed outcomes of 1,112 patients suspected of having metal allergies. Patients were seen from January 1, 2000, through December 31, 2009. Patch testing was performed with 42 metal preparations (6 in the standard series, 36 in the metal series).
Results: Patch testing most commonly was performed for patients with oral disease (almost half the patients), hand dermatitis, generalized dermatitis, and dermatitis affecting the lips, legs, arms, trunk, or face. At least one positive reaction was reported for 633 patients (57%). Metals with the highest allergic patch-test reaction rates were nickel, gold, manganese, palladium, cobalt, Ticonium, mercury, beryllium, chromium, and silver. Metals causing no allergic patch-test reactions were titanium, Vitallium, and aluminum powder. Metals with extremely low rates of allergic patch-test reactions included zinc, ferric chloride, and tin. Reaction rates varied depending on metal salt, concentration, and timing of readings.
Conclusion: Many metals not in the standard series were associated with allergic patch-test reactions. The many questions raised by these findings, concerning patch testing with individual metals, will be the subject of future studies.


Metals are ubiquitous, and some metals (eg, nickel) are well recognized as a common cause of allergic contact dermatitis. The standard (baseline) allergen series used in patch testing contains the metals most commonly known to cause allergic contact dermatitis. However, for select patients, we perform additional testing with a special series of metal allergens.

We have previously published our experience with individual metal allergens and with groups of metals, and we have also examined the relevance of metals in particular clinical settings. These reports include a retrospective study of palladium sensitivity,[1] reports on patch testing with metals in the standard allergen series (part of our reports on patch testing with the standard series),[2,3] a report of the results of a pilot study questioning whether oral metal use may be associated with oral squamous cell carcinoma,[4] and a retrospective study of patch testing before and after metal device implantation.[5]

Because relatively few reports have described the rates of patch-test reactions to metals other than those of the standard series, we undertook this study to report our institution's 10-year experience of patch testing with metal allergens. The format of this article is similar to those reporting findings from the standard series (numerous publications from the North American Contact Dermatitis Group and others). We believe that there is value in publishing a broad overview of patch-test results, even if firm and meaningful conclusions cannot be drawn from these data. We believe that the readers may find this article helpful as they patch-test their patients with metal allergens because it delivers a fairly comprehensive overview of the rates of reaction to many different metals, combinations of metals, and different concentrations and preparations that have not been described previously. This subject is a topical one—a report on a Japanese experience has been published recently.[6]


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