The words “eczema” and “atopy” are used interchangeably to refer to a common skin condition called atopic dermatitis. Any skin condition, however, is considered a type of eczema, atopic dermatitis being one. Other types include hand dermatitis, nummular dermatitis, and seborrheic dermatitis. Dandruff is a mild type of seborrheic dermatitis. Diaper rash and the rash that many people get after coming into contact with poison ivy are other types of eczema.

What Causes Eczema?

One type of eczema, irritant contact dermatitis, develops after frequent exposure to a mild irritant such as a detergent or brief exposure to a strong irritant such as battery acid. Another type, allergic contact dermatitis, develops when an allergen (substance to which a person is allergic) touches the skin. Common allergens include poison ivy and nickel. A nickel allergy is one of the most common causes of allergic contact dermatitis. Many everyday objects contain nickel, including coins, buttons, jewelry, and eyeglass frames.

The exact cause of other types of eczema is not fully understood. Researchers believe that atopic dermatitis develops when many factors combine. These factors include inheriting certain genes, having an overactive immune system, and having something that dermatologists call a “barrier defect.” A barrier defect is a term that means “gaps in the skin.” These gaps allow the skin to lose water too quickly. The gaps also allow germs and other things too small to see with the naked eye to enter the body.

Seborrheic dermatitis is another type of eczema that seems to develop when a number of factors interact. These factors include the person’s genes, yeast that live on human skin, stress, climate, and overall general health. Research shows that seborrheic dermatitis tends to be severe in people who have the human immunodeficiency virus (HIV). This indicates that the person’s immune system plays a role.

How Do Dermatologists Diagnose Eczema?

Eczema can be easy to diagnose, but a challenge to treat. Teaming up with a dermatologist can help. If your dermatologist suspects any eczema, they will take a complete medical history, ask about your symptoms and examine your skin. This provides enough information to accurately diagnose many types of eczema.

If there are telltale signs what you’re experiencing is an allergic reaction, your dermatologist may order a test called the “patch test.” Patch testing can help identify everyday substances to which a person is allergic.

Eczema Treatments

Before prescribing a treatment plan, a dermatologist considers the type of eczema, extent and severity, patient’s medical history, and a number of other factors. Medication and other therapies will be prescribed as needed to:

  • Control itching

  • Reduce skin inflammation

  • Clear infection

  • Loosen and remove scaly lesions

  • Reduce new lesions

Medical research continues to show that the most effective treatment plan for eczema — regardless of type — involves using a combination of therapies to treat the skin and making lifestyle changes to control flare-ups. Doing so tends to increase effectiveness and reduce side effects from medications.

The type of medication prescribed will depend on many factors, including the type of eczema, past treatment, and the patient’s preference. Topical (applied to the skin) medication is frequently prescribed. If the eczema is more severe, phototherapy (a type of treatment that uses light therapy) or systemic (circulates throughout the body) medication may be prescribed.

Today, there are many effective therapies available to treat the different types of eczema. With proper treatment, most eczema can be controlled.

Keep in mind that eczema can be stubborn. If the signs and symptoms persist, be sure to tell your dermatologist. Sometimes it helps to change how you use the medications or to set aside more time for relaxing activities. Secondary infections (such as staph aureus skin infections) or stress cause flare-ups in many people. A dermatologist can work with you to tailor a treatment plan that meets your needs.