Effects of aluminium chloride added to common patch test substances.

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.

RESULTS

Adding Al-Cl 20.0%/30.0% to Ni identified twice as many patients with contact allergy to nickel compared to Ni without Al-Cl. Adding Al-Cl 20.0%/10.0% to MI, decreased the patch test reactivity compared to MI without Al-Cl. No differences in patch reactivity were noticed when adding Al-Cl to FM I.

CONCLUSION

Al-Cl 20.0% or 30.0% seems to enhance the patch test reactivity to Ni 15.0% aqua.