Exp t'>irimilot 1996: 5: 254-259 t^riiilcd in Dcnnuirk • All riiihl.\ reserved Copyriglil & Munksgaard t996 ExperimerOal Dermatology tSSN 0906-6705 Nickel chloride/chlorides of divalent metal interactions in nickel-sensitive subjects Satitucci B, Cuntiislraci C, Crislaudo A, Picardo M. Nickel chloride/chlorides of divalent metal inleractions in nickel-sensitive subjects. Exp Dertnatol 1996: 5: 254-259. © Munksgaatd, 1996 Abstract: To verify if the counter-ion CI" permits the same inleraclions be- tween nickel and divalent metals with physieochetiiical similarities as the eounler-ion SO4^ does, 50 sensitive subjects to nickel sulfate 5% pel. who pre- viously gave positive patch test reactions either lo 8 |.tl ofaq. nickel sulfale 0.1 M or to 8 |.t 1 of aq. nickel chloride 0.1 M, or to both, were patch retested si- tnultaneously to 8 |il of, tespectively, aq. nickel sulfale 0.1 M and aq. nickel chloride 0.1 M, and to 8 |J I ofaq. mixed solutions eontaining, respectively, niekel chloride 0.1 M-t-niagnesium chloride 0.3 M, nickel ehloride 0.1 M-i- zinc chloride 0.3 M, nickel ehloride 0.1 M-t-zine chloride 0.5 M. nickel chlo- ride 0.1 M -t- tnanganese ehloride 0.3 M, and nickel ehloiide O.I M -i- tnanga- nese ehloride O.5 M. Whilst 4 subjects gave a positive pateh test response to otily tiiekel sulphate, 8 gave a positive response lo nickel ehloride alone atid the remaitiing 38 gave a eoncotiiilant positive response to bolli. In all stihjeets who gave positive tespotises lo niekel ehloride, the ehlorides of divalent met- als were not able to itihibil or reduee Ihe positive reaetion. 25 heallhy subjeets pateh tested to both single salts and mixed solutions, and all gave negative re- sponses. 9 of the 50 subjects, 4 who previously gave positive reactions lo only niekel ehloride 0.1 M, and 5 with eoneotnitaiit teaetions ol equal intensity to both niekel ehloride and niekel sulfate 0.1 M, were paleh tetesled sitnultane- ously to 8 |al of, respectively, aq. niekel sulfale O.I M, aq. niekel ehloride 0.1 M and aq. mixed solutions eontaining niekel sulfale (0.1 M) mixed with sul- fates (0.3 M) and niekel ehloride (0.1 M) mixed with ehlorides of Mg, Zn, Mn (0.3 M). Whilst Ihe tnixed sulfate solutions wete able to reduee niekel sulfale, O.I M pateh tesl positive reactions, those eonlaining ehlorides, at all coneen- trations tested, did not inhibit Ihe niekel ehloride reaetions in any of the sub- jeets. The results of the lesLs to chlorides, eotnpared lo lliose reaehed on test- ing to sultates of the same tnelals, lead us lo hypothesize that the atiion proba- bly affeels Ihe uptake and loeal tissue dislribution of the tnetal, tnodulating in this way, together wiih the individual eutaneous ligands, its effeets. H. Santucci, C. Cannistiuci,, A. Cristaudo and M. Picardo Servizio Aiiergoiogia, istituto San Galiicano, Via San Gaiiicano 25a, 00153 Roma, itaiy Key words: chlorides - divalent metais - nici<ei- sensitive subjects Baidassarre Santucci. istituto San Gaiiiacano, Via San Gaiiicano 25 a. 00t53, Roma, itaiy Accepted for pubiication 31 January 1996 Nickel dertnatitis teprescnts the most frequetil type of alletgic dertnatitis seen in our countty. This wide- spread occurrence is due both to the frequent and el- evated exposures to the tnelal (1) and lo its chemical properties. Nickel allergic contact dertnalilis is usually iden- tilied by patch testing to nickel sulfate 5% pet. Al- though nickel chloride is considered more impor- tant due to its higher daily nickel exposure, it is not used in patch testing because of its irritant proper- ties (2). A comparative study of the effects exerted by these 2 salts on the skin of the nickel-sensitive sub- jects may be performed on patch testing lo the satne nutnber of tnoles (3). However, in evaluating the nickel action on the skin, the influence exetted by the anion moiety, i.e., the chloride versus sulfate, on the pcncltation of the nickel ions should be consid- ered. It has been reported (4) tbat the penetration of nickel varies in accordance with the particular salts applied on the skin. In a previous paper (5), we evaluated the inllu- 254