Diagnosing Eczema

What is eczema?

Eczema is the medical term used for a group of health conditions characterized by inflamed, irritated, itchy patches of skin. It can develop at any age, and approximately one in 10 people will develop some type of eczema in their lifetime. It is generally a chronic (long-term) condition that involves periodic flare-ups; however, it can also be acute (short-term).

There are various types of eczema. However, atopic dermatitis is the most common form, and the two terms are often used interchangeably.

How is eczema diagnosed?

There is no definitive test to diagnose eczema. Instead, a diagnosis is typically based on a medical history and physical exam. Allergy testing and a biopsy may also be recommended.

• Medical history
  A medical history involves a medical professional asking questions about the location of the symptoms, the duration of symptoms, and if anything makes the symptoms better or worse. They may also ask about any allergies, hay fever, or asthma and if there is a family history of eczema.
• Physical exam
  During a physical examination, a medical professional examines the skin for redness, dryness, or other irritation, taking note of the affected areas of the body. A physical exam can help determine if symptoms are caused by eczema or another skin condition.
• Allergy tests
  If allergic eczema is suspected, the individual may be referred to an allergist for a patch test or other allergy skin test. These tests can help determine if allergies are triggering the eczema. During a patch test, common allergens are placed on patches and attached to the individual's back for up to 48 hours. The patches are then removed, and the skin is examined for any reactions.
• Skin biopsy
  In some cases, a skin biopsy may be ordered. A biopsy involves the removal of a small sample of skin from the affected area. The sample is then sent to a laboratory for testing. A biopsy can help pinpoint the cause of skin irritation.