Eczema and Food Allergies

Eczema, also known as atopic dermatitis, is a chronic skin condition which is characterized by patches of red, scaling, very itchy skin. It can occur in any age group but is more common in young children.

There is a vicious cycle in which itching leads to scratching, which in turn leads to more itching. Skin patches can become scarred and thickened. Secondary infection with bacteria such as strep or staph can complicate the skin lesions.

In younger infants, the rashes often start on the cheeks and face. In older infants, the patches are often on extensor surfaces such as on the elbows, thighs and knees, and also behind the ears. Older children and adults display rashes on the neck and on flexor surfaces such as behind the knees or the front of the elbows.

Different triggers can cause eczema flare-ups. Dry skin is an important contributing factor; eczema is often worse in the winter when the humidity is lower. Washing the skin too frequently contributes to the problem. Paradoxically, too much water dries the skin due to evaporation.

Recent studies have shown that, in more than one-third of children with eczema, food allergies are a major trigger. Double-blind placebo-controlled food challenges (DBPFC) have been performed in research settings. These tests are called “double blind” because neither the patient nor the investigator knows what foods are contained in gelatin capsules. Some of the capsules are “placebo controlled,” which means they contain inert substances. Through these tests, researchers have been able to prove that some foods cause eczema flares within a couple of hours after exposure.

Known food triggers which may cause eczema exacerbations include milk, eggs, peanuts, wheat, soy and fish. However, patients with eczema may react to one or more — or none– of the foods on the list.

Eczema patients, especially children, should be tested for food allergies. This can be done through either a skin test (prick test) or a blood test (RAST). The skin testing is more sensitive; the RAST test is safer for some patients, especially when there is a history of severe, life-threatening food allergies such as to peanuts or shellfish.

It is particularly important to identify food allergies in patients with eczema so they can avoid those foods. Food allergies do change as children grow older. Many children will outgrow food allergies, but some develop new food allergies as they grow older. Follow-up testing can pinpoint these changes.

The only treatment for food allergies is avoidance. An epinephrine self-injector, called either Epi-pen or Twin-ject, should be readily available for those with severe food allergies.

The mainstay for eczema treatment is skin moisturization. Moisturizers such as Eucerin, Aquaphor or Cetaphil should be applied regularly, especially after taking a bath and before bed. Mild, fragrance-free soaps and detergents should be used for bathing and in the laundry. Adequate house humidity in winter also is helpful.

Topical steroid ointments and creams are effective. The required strength depends on the severity of the skin lesions and the patient’s age. Topical steroids should be used sparingly on the face and in young children, as they can thin out the skin. Elidel and Protopic are creams which are alternatives to steroids in children over two years old. They are also especially useful in patients with facial eczema.

Antihistamines are important to reduce itching. Long-acting antihistamines taken once daily are usually effective in breaking the scratch-itch cycle. These include Zyrtec, Xyzal, Allegra, Atarax, Clarinex or Claritin.

Treatment of secondary infection is also important. Breaks in the skin due to scratching can lead to local staph or strep infections. Treatment with either topical or oral antibiotics also can promote lesion healing.

The long-term outlook for eczema in children is good, as many outgrow the problem by their teenage years.