Patch testing with nickel sulphate under occlusion for five hours

Routine patch testing is usually performed with the allergens under occlusion for 48 h, but a shorter occlusion time would of course be more convenient for the patient. In this study, nickel was chosen as the substance with which to investigate whether routine patch testing with allergen exposure for 5 h is possible. Patch testing, using dilutions of nickel sulphate under occlusion for 48 h and 5 h, was compared in 8 nickel-sensitive females. The results show that equivalent patch test reactions were achieved when using higher concentrations of the nickel solutions under occlusion for 5 h.