Medical dermatology · Allergy & itch
Contact Dermatitis & Patch Testing
Patch testing identifies allergens causing contact dermatitis, such as nickel, fragrances, preservatives and hair dye. Small amounts of allergens are taped to the back for 48 hours and read over several days by a dermatologist.
Overview
Contact dermatitis from cosmetics and hair dye is common in Korea. Knowing the exact allergen allows lasting avoidance.
At a glance
Process
Application day, removal at 48 hours, readings at about 72 to 96 hours.
Preparation
Avoid steroids on the back and sun exposure beforehand.
Common allergens
Nickel, PPD in hair dye, fragrance, preservatives.
Frequently asked questions
Can I shower during patch testing?
Keep the back dry until the final reading.
Is it painful?
No, though positive spots may itch.
Is patch testing available at clinics?
Some specialist clinics and hospitals offer it; call ahead.
Related
Choose a specialist
Medical skin conditions need a dermatology specialist
Many Korean “skin clinics” focus on cosmetic procedures and may not treat skin disease. Board-certified dermatologists (피부과 전문의) are trained to diagnose and treat it, and medical dermatology is partly covered by Korea’s National Health Insurance. This page is general information, not medical advice.