The goal of this study was to highlight recent findings, particularly with new and old allergens, trends, contact allergy diagnosis, and reasons. Nickel remains the most common cause of contact allergy in women, and piercings are a significant risk factor. Countries with a long history of regulating contact allergens have the lowest level of nickel and chromium contact allergy in Europe. Terpenes that have been oxidised, such as limonene, linalool, and, in some countries, geraniol, are among the most common causes of scent contact allergy. Methylisothiazolinone is still generating significant issues as a result of undetected exposures. Acrylates are emerging allergens, and 2-hydroxyethyl methacrylate has been added to the 2019 baseline series update, as numerous new instances have been reported due to acrylate-based nail polish and adhesive (isobornyl acrylate) in insulin pumps. More than ten additional allergens have been identified and must be considered when diagnosing contact allergy.

Allergic contact dermatitis is a common condition, but it is often difficult to diagnose due to the large number of potential contact allergens. While the primary allergens remain the same, additional important culprits, particularly among acrylates, have been discovered.