Allergic contact dermatitis remains a commonly encountered condition in dermatology. Contact allergen prevalence fluctuates over time, making ongoing surveillance essential for detecting trends and identifying emerging allergens.

To determine the prevalence and trends of top allergen patch test-positive patients over a 10-year period.

The medical records of 906 patients who underwent patch testing at the hospital between 2012 and 2021 were retrospectively reviewed. Clinical data and patch tests results with clinical relevance from consultation records were extracted and analyzed.

In the 10 years, data from 996 patients patch tested with European baseline series of contact allergens were analyzed. The overall positivity rate was 64.25%. The predominant allergens investigated during the previous decade include nickel sulfate (19.60%), fragrance mix I (8.70%), potassium dichromate (5.99%), cobalt chloride (5.92%), and p-phenylenediamine base (5.92%). The trend in our study aligns with global patch test data, with nickel sulfate consistently leading as the most frequent allergen.

The study emphasizes the need for regular monitoring and updating of the standard patch test series to ensure its clinical relevance and improve patient care.