Original Article: http://www.mayoclinic.com/health/medical/IM02933
- Poison ivy plant with berries
- Poison ivy rash
- Poison ivy plant
- Contact dermatitis on the wrist
- see all
- Slide show: Types of dermatitis
Patch testing can be helpful in determining if you're allergic to a specific substance. Small amounts of different substances are placed on your skin under an adhesive coating. Your doctor then checks for a skin reaction under the patches.