Contact allergy and sociodemographic characteristics.

The aim of the study was to determine the frequency of positive patch test reaction to different contact allergens according to patients age, sex, occupation and clinical features. Between 1999 and 2003, patch testing was performed in 3,293 patients with respective clinical diagnoses. Patch testing was done by the standard technique proposed by the International Contact Dermatitis Research Group (ICDRG). Study results showed statistically significant differences in patch test response according to sex and age for three allergens (cobalt chloride, nickel sulphate and thiomersal); according to occupation for nine allergens (cobalt chloride, nickel sulphate, balsam of Peru, fragrance mix, thiuram mix, wood tars, neomycin sulphate, thiomersal and detergents), and clinical diagnosis for two allergens (nickel sulphate, and wood tars). The most common and relevant allergens were: nickel sulphate, cobalt chloride and carba mix. They were found in all examinees regardless of age, sex, occupation and diagnoses. The increased awareness of allergens and their potential sources may help to limit the usage of these chemicals in manufacture of consumer products.