Nickel release from nickel-plated metals often induces allergic contact dermatitis, but, for nickel-containing stainless steels, the effect is not well-known. In this paper, AISI 304, 316L, 303 and 430 type stainless steels, nickel and nickel-plated materials were investigated. 4 tests were performed: patch tests, leaching experiments, dimethylglyoxime (DMG) spot tests and electrochemical tests. Patch tests showed that 96% of the patients were intolerant to Ni-plated samples, and 14% to a high-sulfur stainless steel (303), while nickel-containing stainless steels with a low sulfur content elicited no reactions. Leaching experiments confirmed the patch tests: in acidic artificial sweat, Ni-plated samples released about 100 micrograms/cm2/week of nickel, while low-sulfur stainless steels released less than 0.03 microgram/cm2/week of nickel, and AISI 303 about 1.5 micrograms/cm2/week. Attention is drawn to the irrelevance of the DMG spot test, which reveals Ni present in the metal bulk but not its dissolution rate. Electrochemical experiments showed that 304 and 316 grades remain passive in the environments tested, while Ni-plated steels and AISI 303 can suffer significant cation dissolution. Thus, Ni-containing 304 and 316 steels should not induce contact dermatitis, while 303 should be avoided. A reliable nitric acid spot test is proposed to distinguish this grade from other stainless steels.

Forty-two cases of contact sensitivity to N-isopropyl-N'-phenylparaphenylenediamine (IPPD), an amine antiozonant used in rubber manufacture, were collated from several firms and plants dealing with tyres. Ten motor car tyres manufactured by eight different firms all induce sensitivity reactions in seven subjects allergic to IPPD. Clinical cross-reaction tests show that 100% of the subjects sensitive to IPPD are also sensitive to N-phenyl-N'-cyclohexy-paraphenylenediamine (CPPD), another amine antiozonant, and 37% to paraphenylenediamine (PPD). The various types of tyres were analyzed by gas chromatography and then by infra-red and thin-layer chromatography where necessary. None of the 12 tyres examined was found to be free from aromatic amines. Test reactions carried out with various automobile accessories on subjects allergic to IPPD in tyres gave positive results precisely in those cases where the articles contained IPPD. The authors then studied occupational sensitivity to N-dimethyl-1,3 butyl-N'-phenylparaphenylenediamine (DMPPD), a rubber antiozonant purported to be non-sensitizing and marketed in the United States. The The DMPPD tests were positive for all the IPPD-allergic patients tested; there is no doubt as to the allergenic nature of DMPPD. The irritant and sensitizing potentials of the four amines in question were tested in laboratory animals: PPD proved to be the most allergenic product, IPPD the least allergenic, and DMPPD and CPPD seem to give identical results. All these products produce positive cross-reactions in varying degrees of severity.

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3 cases of contact dermatitis from ginkgo fruit are reported. Swelling of the prepuce can be the only clinical sign of intolerance, as was observed in 1 case. Diagnosis of contact dermatitis to ginkgo fruit should be made in cities where female ginkgo trees grow, in Chinese, Japanese and South-East Asian subjects, who are aware of the ginkgo nut's culinary qualities within the fruit, as well as in children who play with the fallen fruits as "marbles".

In 22 nickel-sensitive subjects, 57 metal clothing objects were said to be not tolerated (37) or tolerated (20). They were analysed by X-ray energy dispersion in electron microscopy, and by the dimethylglyoxime spot test. The correlation between the analytical results and the statements of patients is discussed. Patch tests to nickel-plated metal samples with various thicknesses of chromium (0.25 mu to 1 mu) or gold/copper/cadmium (0.5 mu) were performed in human subjects or in guinea pigs sensitive to nickel. Surface-plating and anticorrosive techniques, as well as the results in nickel-sensitive subjects, are described and discussed. Good tolerance will not be obtained under experimental conditions if nickel in any form is a component of the object. It is to be hoped that appropriate regulations will prohibit the use of nickel in the manufacture of clothing objects.