Depending on your pattern of skin symptoms, the doctor will ask about your:
Contact with poisonous plants
History of exposure to irritating chemicals at work or at home
Personal and family allergy history
In some cases, your doctor may need to ask for the names of specific ingredients in your personal care products. In particular, the doctor will ask about:
Antibiotic skin ointments.
After reviewing your history of allergies and chemical exposures, your doctor usually can confirm the diagnosis of contact dermatitis by examining your skin.
If your doctor suspects allergic contact dermatitis and cannot identify the likely allergen, your doctor may refer you to a dermatologist for patch testing. Small amounts of specific allergens are applied to the skin of your back, and then covered with tape. After 48 hours, the doctor removes the tape. He or she examines the skin for signs of an allergic reaction. A second reading is done after three to seven days.