A retrospective analytical study of patch testing in suspected contact dermatitis patients of Teaching Hospital, Batticaloa

Background: Contact dermatitis is inflammation of the skin caused by contact with external agents. Patch test is the best diagnostic tool for allergic contact dermatitis(ACD) and its appropriate use can minimize diagnostic errors and increase quality of life of patients by identifying and avoiding causative substances.

Objectives: The aims of this study were to confirm ACD by patch testing in suspected patients and to identify the correlation between the suspected allergen and the actual positive allergen identified by patch testing.

Method. Suspected patients with ACD were patch tested using either European standard or shoe series appropriately. Collected data using a questionnaire along with the patch test results were analyzed retrospectively.

Results: A majority of the patients had foot dermatitis (28.5%). The most common positive allergens were potassium dichromate (38.7%) and paraphenyldiamine (22.5%) and nickel (22.5%). 53.1,% of the cases correlated with the suspected pre-patch test allergen and the actual positive allergen.

Conclusion: Patch test should be used frequently for the diagnosis of ACD. Developing the patch test kit to suit Sri Lankan patients is an emerging need.