This study suggests that FLG null mutations may be a risk factor for the development of nickel sensitization. However, ear piercing was a much stronger risk factor in our general population and we could therefore identify a positive association only in women without ear piercings. Contact sensitization to specific chemicals is related to treatment exposure.

FLG null mutations were significantly associated with hand eczema (< 12 months) in subjects with atopic dermatitis. Combined atopic dermatitis and filaggrin null mutation status was strongly associated with early onset of hand eczema and hand eczema persistence.

Dillarstone's prediction was confirmed as the prevalence of contact allergy to individual preservatives remained relatively stable. However, the overall burden of preservative allergy seemed to increase. Introduction of new preservatives may add to the burden of contact allergy.