Most cases of atopic dermatitis can be diagnosed from a medical history and a physical exam. You will be asked about your family history of allergic conditions, when the itch first started, and when the rash first appeared. What the rash look likes and where it is located will help your health professional make a diagnosis. Your or your child's condition is more likely to be atopic dermatitis if a parent or brother or sister has an allergic condition (especially asthma, allergic rhinitis, or atopic dermatitis).

Allergy testing

Your health professional may recommend allergy testing to identify any factors that are related to atopic dermatitis flares. Allergy testing is most helpful for people with atopic dermatitis who also have respiratory allergies or asthma. Allergy testing can help identify certain allergens. However, test results are often false-positive. For more information, see the topic Allergy Tests.

If a specific allergen is thought to trigger your atopic dermatitis, you and your health professional will discuss how to eliminate it from your diet or environment while closely observing and recording your symptoms.