Atopic Dermatitis (Eczema): Triggers

There is no known way to keep from getting atopic dermatitis in the first place. But if a person has the condition, it often is possible to minimize the number of outbreaks by avoiding triggers. These triggers fall into four basic categories:

• Things that dry out the skin: Dry skin is a key feature of atopic dermatitis, so conditions that exacerbate dryness are triggers for many patients. For instance, an environment of low humidity or extreme air temperatures--either hot or cold--can remove moisture from the skin. Harsh soaps and frequent washing without applying moisturizers can also bring on flares. Fragrances and other additives in some soaps and cleansers may irritate the skin directly.

• Emotional stressors: Anger, embarrassment, and other strong emotions can cause the skin to flush. This can make it itchy, which leads to scratching. This can then cascade in a perpetual cycle of dermatitis.

• Allergies: Although the exact mechanisms are not fully understood, allergic reactions often trigger a rash and a general itchy feeling, which can start the scratch-itch cycle. Two types of allergens are commonly linked to atopic dermatitis—food allergens (such as milk, eggs, peanuts, soy, wheat and fish) and airborne allergens (including dust mites, animal dander, and pollen). It is important to recognize that a positive allergy skin or blood test shows sensitization but does not always indicate a proven clinical allergy. So be sure to get a careful evaluation from an allergy specialist before making changes to your diet or your home environment.

• Skin infections: Bacterial and viral infections of the skin both can bring on atopic dermatitis flares. Bacteria can secrete toxins into the skin, sparking an immune reaction, which prompts inflammation. A common bacterial culprit is Staphylococcus aureus (“staph”). Some atopic dermatitis patients are colonized by or infected by methicillin resistant S. aureus (MRSA). Herpes viruses, which cause cold sores, also are linked to flares. A widespread infection by herpes simplex virus that requires immediate medical attention is called eczema herpeticum. In addition, outbreaks of herpetic lesions around the eyes should be evaluated by an eye specialist. Two other viruses that can cause problems for atopic patients are Molloscum contagiosum and Vaccinia. This last virus may cause severe skin reactions (eczema vaccinatum) in individuals with active, but even past histories of, atopic dermatitis after immunization against smallpox with vaccinia. The vaccine contains a live virus, and because atopic patients often have breaks in the skin barrier because of the rash, as well as a defective immune response within the skin, that virus can spread easily throughout the skin and into the body. The infection can be severe even in patients whose atopic dermatitis has been in remission. For this reason, people with atopic dermatitis should consult with their doctor before getting the smallpox vaccine.

Atopic dermatitis is a highly individual disease. Some patients are sensitive to many triggers; others react to only one. It is important for patients to work closely with their healthcare providers to identify their own particular triggers.