Positive patch tests to palladium are not mere cross-reactivities to nickel but relevant diagnostic findings

Radoslaw Spiewak

Jagiellonian University Medical College, Department of Experimental Dermatology and Cosmetology, Krakow, Poland

Source: Spiewak R. Positive patch tests to palladium are not mere cross-reactivities to nickel but relevant diagnostic findings. Allergy 2011; 66 (Suppl 94): 689-690.

Background: Palladium (Pd) is present in every automobile catalytic converter, computer, mobile phone, or LCD television. Palladium alloys are used in dentistry and orthopaedics. Following EU restrictions on nickel (Ni) use in jewellery, Pd has replaced Ni in "white gold" alloys. This has led to increase in numbers of patients with contact allergy to Pd. Until recently, positive patch tests to Pd were mostly regarded as a mere cross-reactivity with Ni.

The aim of the present study was to analyse clinical characteristics of patients with primary allergy to palladium.

Methods: In June 2010, the Polish Baseline Series was supplemented with propolis and palladium. Since then, I had the opportunity of testing 85 patients to this series (19 males, 65 females, aged 8-70, median 37 years) with suspicion of allergic contact dermatitis (ACD).

Results: In the analyzed group, 28 (32.9%) patients were Ni-positive and 17 (20.0%) Pd-positive; 15 (17.6%) patients were positive to Ni but negative or doubtful to Pd. Four (4.7%) patients reacted to Pd but not Ni. Two patients (2.4%) were found with reactions to Pd clearly stronger than to Ni, which suggests that their primary hypersensitivity was Pd allergy, while response to Ni - a cross reaction. All the six person were women aged 18-70 years. In three of them, it seems apparent that testing to Pd provided information pivotal to their diagnostic process (Table): To most doctors, history given by Ms "A" and would be a "dead sure" indicator of nickel allergy - except the rather surprising fact that the patch test to nickel remained negative, along with chromium and cobalt - two other metals included into European Baseline Series. Instead, positive patch test to palladium (and gold) has solved the case (Pd-Au alloy is jewellery "white gold"). In Ms "B", all the evil would be ascribed to cobalt, if not tested with Pd. If Ms "C", a cashier, was tested only to Ni, the positive reaction would seem a sound explanation of her case. However, patch test to Pd resulted in an extreme reaction, suggesting that Ni was a mere cross-reactivity rather than the main cause. The relevance of Pd patch tests in the three remaining patients remains unclear.

Conclusion: Over past years, palladium has become broadly present in our surroundings. Combined with itssensitizing properties, this hapten has acquired big importance for allergists and should be included into routine patch testing.

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Patch testing in Krakow (Cracow), Poland

Institute of Dermatology, Krakow, Poland

Patient Age Pd Ni Other metals Indications for patch tests Metal-related symptoms Exposure to metals
Ms "A" 32 y.o. (+) (-) Cr(-), Co(-), Au(+), Cu(+), Mn(+) Intolerance of jewellery, planned dental implants Eczema to jewellery, including gold and non-precious metals Typical everyday exposure
Ms "B" 18 y.o. (++) (-) Co(++) Intolerance of metals and detergents Itching provoked by earrings Typical everyday exposure
Ms "C" 27 y.o. (+++) (++) Cr(-), Co(-) Intolerance of metals and cosmetics Reactions to wrist watch, earrings, jeans buttons Cashier
Ms "D" 38 y.o. (+) (-) Cr(-), Co(-), Au(+), Ag(-) Intolerance of cosmetics, household detergents, and textile finishes None reported Typical everyday exposure
Ms "E" 70 y.o. (+) (-) Co(-), Au(+) Intolerance of household detergents None reported Typical everyday exposure
Ms "F" 46 y.o. (++) (+) Cr(-), Co(IR), Hg(-) Intolerance of cosmetics None reported Cashier
IR, irritant reaction.

Related articles:

  1. Spiewak R. Patch testing for contact allergy and allergic contact dermatitis. Open Allergy J 2008, 1: 42-51.
  2. Spiewak R. Atopy and contact hypersensitivity: a reassessment of the relationship using objective measures. Ann Allergy Asthma Immunol 2005, 95 (1): 61-65.
  3. Spiewak R, Pietowska J, Curzytek K. Nickel: a unique allergen - from molecular structure to European legislation. Expert Rev Clin Immunol 2007, 3 (6): 851-859.

© Radoslaw Spiewak (contact).
This page is part of the www.RadoslawSpiewak.net website.
Document created: 29 June 2012, last updated: 30 June 2012.