Sometimes, patients with a history of metal intolerance react negatively or doubtfully to nickel at patch testing.
The aim of the study was to investigate whether aqueous nickel sulfate hexahydrate at 15% and 30% traces more contact allergy than the nickel preparation in the baseline series at 5%.
In the period 1995–2015, more than 800 of 16,059 patients with a negative or doubtful patch test reaction to the petrolatum preparation of nickel at 5% on the day 3 reading were additionally tested with aqueous nickel at 15% and/or 30%.
In this retrospective study with aimed patch testing with aqueous nickel solutions, significantly more (P < 0.001) contact allergy was obtained as compared with the 5% preparation in petrolatum. The 30% solution was significantly better (P < 0.001) than the 15% solution. To demonstrate that patch testing with nickel at 15% or 30% is better than the present testing with 5% requires simultaneous testing with the 3 nickel preparations.
From the Department of Occupational and Environmental Dermatology, Lund University, Skåne University Hospital, Malmö, Sweden.
Address reprint requests to Magnus Bruze, MD, PhD, Department of Occupational and Environmental Dermatology, Lund University, Skåne University Hospital, Jan Waldenströms Gata 16, S-205 02 Malmö, Sweden. E-mail: firstname.lastname@example.org.
The authors have no funding or conflicts of interest to declare.