While eczema cannot be cured, most cases can be controlled by:

• Making lifestyle modifications to prevent flare-ups
• Seeing a dermatologist for treatment
• Using medication as prescribed

This approach tends to prevent inflammation and itching and keeps eczema from getting worse. Dermatologists recommend that treatment be sought at the onset of signs and symptoms. When therapy begins early, it often reduces severity and duration.

Effective treatment requires a correct diagnosis; however, it is not always easy to distinguish one type of eczema from another or from similar skin conditions. Dermatologists have the medical training and experience needed to determine if eczema is present — and if present, which type. To diagnose eczema, dermatologists examine the skin and ask about:

•  When the skin condition first appeared
• Signs and symptoms, such as long-term pruritus (itching) or recurring dermatitis (inflammation of the skin)
•  Certain circumstances that may aggravate the condition, such as excessively dry air or emotional stress
•  Family medical history, including questions about close blood relatives who have asthma, hay fever, or eczema
•  Personal medical history

In some cases, a skin biopsy may be performed to rule out other causes.

Allergies are more common in individuals with atopic dermatitis, and allergy testing may be considered when a patient has:

• Significant indications of allergies, such as gastrointestinal symptoms (e.g., nausea, vomiting, or diarrhea and colic in infants) or hives

• Been poorly responsive or unresponsive to treatment

If a food allergy is suspected, testing for allergic reactions to eggs, milk, peanuts, soy, wheat, fish, and tree nuts (e.g., walnuts, cashews) are usually performed as these foods are responsible for 85% of all food allergies. A positive allergy test does not confirm the food allergy. A suspected food allergy must be subjected to a "challenge." A challenge is conducted by having the patient eat the suspected food and observing the patient for a reaction. Even a challenge does not guarantee that the food is the trigger because:
1) another trigger may be present and causing the reaction or
2) the patient’s reaction may be delayed.

Consequently, allergy testing has limited value. However, it is useful for eliminating foods that cause immediate and severe reactions or welts.

Dermatologists may use a “patch test” to determine if the patient has allergic contact dermatitis, a type of eczema that develops when the person has an allergic reaction to a substance that contacts the skin. The reaction generally occurs a few hours after the substance contacts the skin and settles down within a few days if the substance does not contact the skin again. A patch test exposes the patient’s skin to minute amounts of substances that may have caused the reaction. When the test is positive, the dermatologist must determine if the chemical caused the dermatitis and if so, if it is the primary cause or an aggravating factor. Further testing may be necessary.