Changes in the Patch Test Population Over a Ten-Year Period at the Contact Dermatitis Clinic, Siriraj Hospital: A University-Based Tertiary Care Hospital in Thailand

Background: There are several factors which have an impact on patch test results. In the past, comparing the populations between different institutes, without appropriate indicators was difficult. Thus, the MOAHLFA index (Male, Occupational, Atopic dermatitis, Hand dermatitis, Leg dermatitis, Face dermatitis and Age above 40 years) was developed. However, the study of this index in Thailand is limited. Objective: To investigate the MOAHLFA index in patch testing population in the Contact Dermatitis Clinic at Siriraj Hospital. Methods: The clinical parameters of patients who underwent patch testing at Contact Dermatitis Clinic, Siriraj Hospital during 10 years were studied. Results: Our patch test population showed a statistically significant increase in the proportion of male and patients aged above 40 years while a statistical decrease was found in those with occupational skin diseases with a history of atopic dermatitis, and lesions on the hands during a decade. Conclusion: This study revealed patch-test population attending Siriraj contact dermatitis clinic changed in 10-years period. According to MOAHLFA index, the changes were increasing of male, aged >40 years but decreasing of atopic, occupational-related contact allergy patients.