Effects of aluminium chloride added to common patch test substances

Abstract

Background: A modulating effect of aluminium regarding type IV reactions might exist but has not been further investigated. Objectives:The aim of this study was to investigate the effect on patch test reactions when adding aluminium chloride hexahydrate (Al-Cl) to common test preparations. Materials and methods: Al-Cl in different concentrations was added to nickel sulphate 15.0% aqua (Ni), methylisothiazolinone 0.2% aqua (MI) and fragrance mix I 10.0% aqua/ethanol (FM I). The Ni preparations were tested in 120 consecutive patients. MI and FM I were tested in participants known to have contact allergy to the respective allergen. McNemar's test was used to decide which Ni preparation had the highest sensitivity. Wilcoxon signed-rank test was used to calculate pairwise comparison in summarized test score for the preparations with MI and FM I.