Trends in contact allergies to nickel, cobalt, and chromium in Thailand: a 10-year retrospective study

Abstract

Metal contact allergies have consistently ranked among the most prevalent contact allergies globally. However, trends in the allergies vary by region. This study aimed to assess the prevalence and trends of contact allergies to metals in the baseline series over the past decade. It also sought to identify factors associated with the metal allergies comparing to those without metal allergies. We analyzed patch test data for the metallic allergens—nickel, cobalt, and chromium, —collected from January 2013 to December 2022. The rate of all metal contact allergies decreased. Nickel emerged as the most prevalent allergen (21.7%), followed by chromium (9.6%), and cobalt (7.9%). Notable associated factors for metal contact allergies include female sex, occupational exposure, and a history of suspected metal contact allergy. Concomitant positive reactions were most frequently observed with the combinations of nickel and cobalt. A decline in metal contact allergy prevalence in Thailand, correspond to rising popularity in various novel metal substitutes; plastic, resin or natural materials. Dermatologists should also keep track of contact allergy to those metal substitutes.