Patch Testing in Children, Adults, and the Elderly: Influence of Age and Sex on Sensitization Patterns

TLDR

Patch testing of 2,776 consecutive patients (76.5 % female) using a locally revised 34‑allergen series was analyzed for age‑ and gender‑specific differences. Positive patch tests occurred in 48.9 % of patients, with nickel (20.9 %), ethylmercuric chloride (13.2 %), thimerosal (11.8 %), fragrance mix (9.3 %), metallic mercury (8.9 %), palladium (5.8 %), balsam of Peru (3.8 %), copper (3.7 %), cobalt (3.3 %), and chromium (2.3 %) as the top ten sensitizers; additional allergens above 1 % included ethylmercuric chloride, metallic mercury, copper, propolis, and propylene glycol; females showed higher rates for nickel, cobalt, and palladium; sensitization peaked at 62 % in children under 10 and fell to 34.9 % in those over 70, with nickel and thimerosal decreasing with age while fragrance mix and metallic mercury remained stable.

Abstract

Patch testing was done on 2776 consecutive patients (76.5% female) with a locally revised standard series of 34 contact allergens and the results analyzed for age- and gender-specific differences. At least one positive epicutaneous test reaction occurred in 48.9% of patients. Nickel (20.9%), ethylmercuric chloride (13.2%), thimerosal (11.8%), fragrance mix (9.3%), metallic mercury (8.9%), palladium (5.8%), balsam of Peru (3.8%), copper (3.7%), cobalt (3.3%), and chromium (2.3%) were the 10 most important sensitizers. The following tested allergens with sensitization rates of more than 1% were not part of the usual standard series: ethylmercuric chloride, metallic mercury, copper, propolis (1.3%), propylene glycol (1.0%). Reactions to nickel, cobalt, and palladium, but not to chromium, were significantly more abundant in females (p < 0.002, chi-squared test). The overall sensitization rate was highest in children less than 10 years old (62%) and decreased steadily, to be lowest among patients more than 70 years old (34.9%). The rate of positive reactions to nickel and thimerosal decreased with age, while fragrance mix and metallic mercury stayed at the same level through all age groups.