Background.Allergic contact dermatitis (ACD) is a common diagnosis in patients seen at the outpatient department. Patch test confirms and identifies the causative chemicals in these patients. The Environmental Dermatology Unit of St. Luke's Medical Center, Philippines has been conducting a 70-allergen standard patch test series for more than 10 years. This is the first retrospective study on patch tested patients in this institution.
Objectives. This study aims to determine the clinical profile; analyze the epidemiology on age, sex, occupation, diagnoses, most common dermatitis sites; and, determine most common allergens among patients who underwent patch testing in the Environmental Dermatology Unit from 2003 to 2014.
Methods. Patch test results from January 2003 to December
2014 were collated and tabulated. Frequencies and percentages were obtained. Correlation of prevalence and relevance of allergens were calculated using the Significance-Prevalence Index Number (SPIN).
Results. A total of 784 patients were patch tested from January
2003 to December 2014. The majority of the patients were middle• aged, females, and Asians. The most common occupations were professionals or managers. Among all allergens tested, nickel has the highest number of positive reactions and relevance. Thimerosal and gold sodium are two other allergens with high relevance.
Conclusion. Patch test is an important diagnostic tool
that confirms allergic contact dermatitis. The clinical profile of the patch tested patients reflected similar findings with other countries. Likewise, nickel is the most common allergen. Unlike North America and Europe, thimerosal and gold sodium are more frequently seen in this predominantly Asian study population.
Key words. patch test, allergic contact dermatitis, allergens,