Contact sensitization to metals in Taiwan

Background: Correlation of several patient factors with contact sensitization to nickel, cobalt, chromate, and other metal allergens has not been reviewed in the Taiwanese population. Objectives: A retrospective analysis was performed to define the characteristics of patients with positive patch tests to metals in a tertiary referral medical centre between 1978 and 2003. Patients and Methods: Patch test data of 3559 patients at a medical centre in Taiwan from 1978 to 2003 were retrospectively analysed. Contact sensitization to metals was defined as a positive reaction to at least one of the metal substances in the patch test series. Chi-squared test, Fisher’s exact test, and multivariate logistic regression were used for statistical analysis. Results: Female patients were more likely to have contact sensitization to metal allergens except chromate or mercurochrome. Patients who reacted to chromate were more likely to be male, with an occupational correlation, older age, and a site of predilection towards the extremities. Within the first and sixth decades of age, thimerosal and chromate were the leading causes of metal contact sensitization, respectively. Nickel was the major metal sensitizer among the other age groups. Conclusions: Several patient factors were characterized related to metal sensitization in the Taiwanese population. The sources of exposure were further discussed.