Background: Thailand, an agricultural country developing into an industrial country, has differences in work environment, substance exposure, and climate. These factors may lead to a distinct epidemiology of occupational contact dermatitis (OCD).

Objective: To study the prevalence of allergic and irritant occupational contact dermatitis in Thailand.

Material and Method: The records of patients diagnosed of OCD and patch tested between 2006 and 2010 at Siriraj University Hospital were retrospectively reviewed.

Results: From 885 patch tested patients, 194 (21.9%) had OCD. Of those 194 patients, 76.8% were female and 23.2% were male. Allergic contact dermatitis (ACD; 76.3%) was found to be more common than irritant contact dermatitis (ICD; 24.2%). The common affected part was hands (51.5%). The most frequent occupation was wet work (35.1%), followed by office work (24.7%), industrial work (16%), and medical personnel (13.4%). The most common occupational allergens were nickel sulfate (33.1%), potassium dichromate (19.6%), and carba mix (15.5%). Water (56.1%), foods (4.9%), and oil/grease (2.4%) were the most common occupational irritants.

Conclusion: In our setting, allergic OCD was more common than irritant OCD. Nickel sulfate was the most common occupational allergen. Occupational ACD and ICD are most commonly found in industrial work and wet works, respectively.

Keywords: Prevalence, Epidemiology, Occupational contact dermatitis, Allergic contact dermatitis, Irritant contact dermatitis