Overview and Symptoms:
Eczema, or atopic dermatitis, is a type of skin rash characterized by itchiness, redness, and scaliness. Eczema may be accompanied by oozing blisters surrounded by red or discolored areas from frequent scratching. It most commonly appears on the knees, elbows, cheeks, and extremities, though it can be seen on other parts of the body as well. Food allergies are among several triggers that can cause or worsen eczema in susceptible people.
Eczema in Children and Adults:
Eczema occurs most commonly in children. Some 10% to 20% of children will develop eczema worldwide, with about half of those being diagnosed before the age of one. Most children with eczema will either completely outgrow their symptoms or find that their symptoms improve significantly by the time they reach adulthood. About 10% of eczema cases occur for the first time in adolescents or adults.
Associated Conditions and Risk Factors:
Eczema is associated with a variety of allergic conditions. Among them are asthma, respiratory allergies, and allergic rhinitis. Eczema has a genetic component; children born into families with a history of asthma, hay fever, eczema, or other allergic disorders are more likely to develop eczema.
Eczema and Food Allergies:
About one-third of eczema patients respond to food triggers. Eczema can make allergy testing difficult. It can make skin testing almost impossible. (In these cases, RAST tests may be useful). Food allergens can sometimes cause eczema to worsen or "flare up." In people with eczema and food allergies, strictly avoiding food allergens may help reduce or, occasionally, eliminate symptoms.
Common Food Triggers for Eczema:
The most common food triggers for eczema are eggs, milk, peanuts, soy, and wheat. Among these, eggs are probably associated the most strongly with eczema. Because of the high number of eczema patients who have food allergies, studies recommend that food allergy screening be a part of testing anyone newly diagnosed with eczema, especially children.
Non-Food Triggers for Eczema:
In addition to food allergens, eczema can be exacerbated by stress, physical irritants (like excess dryness or itchy clothing), airborne allergens like dust and pollen, and some infections.
Eczema treatment consists of avoiding any known triggers or irritants (whether allergenic, emotional, or physical), treating skin dryness, and reducing inflammation. Your doctor may treat skin dryness with special lotions or with wet dressings. Drugs that are used to control inflammation include topical corticosteroids like Cultivate (fluticasone) and Dermatop (prednicarbate). Occasionally, doctors prescribe shorter courses of oral steroids like prednisone to treat severe eczema, but these drugs are generally not used for long periods of time.
Studies have examined whether late introduction of solid foods, breastfeeding, or supplements of probiotics (helpful bacteria that live in the small intestines) can help prevent eczema in high-risk children. While studies have not found a compelling reason for parents to delay introducing solid foods beyond the current AAP recommendation of four months, exclusive breastfeeding for four to six months does seem to help. Several studies have shown that probiotic supplements in infants might help prevent eczema, but this research is not considered conclusive. Ask your doctor before giving your infant probiotics.
Living with Eczema and Food Allergies:
Eczema is a major "quality-of-life" disorder for families dealing with it; it can be quite painful and can be distressing for both children and parents.
Allergy testing to determine whether food allergies are a trigger for eczema can be useful in helping ease symptoms of eczema. If you or your child have eczema and are found through testing to be allergic to a food, strictly avoiding that food may help you reduce eczema symptoms. Families may be disappointed, though, to find that a food allergen-free diet isn't a "magic bullet." Not everyone with food allergies and eczema finds that abstaining from food triggers eliminates or even substantially alleviates their eczema (although many do).
Your allergist can give you guidance about what to expect after your allergy testing and can help you relieve symptoms of eczema through medication and home treatment. Your doctor needs to know if an eczema rash becomes painful, unusually swollen, or accompanied by a fever, since these are all signs of bacterial infection. Keep in mind that eczema tends to be most severe in children under the age of five, and that many families will find that children's symptoms are, if not completely outgrown, far less severe as they grow older.
Adkinson, N. Franklin, et al. "Chapter 86: Atopic Dermatitis." Middleton's Allergy: Principles and Practice. 6th Ed. Philadelphia: Mosby, Inc., 2003.
Filipiak, Birgit, et al. "Solid Food Introduction in Relation to Eczema: Results from a Four-Year Prospective Birth Cohort Study." Journal of Pediatrics. Oct. 2007. 151(4): 331-33.
Hill, David J., et al. "IgE Food Sensitization in Infants with Eczema Attending a Dermatology Department." Journal of Pediatrics. Oct. 2007. 151(4): 359-63.
Leung, Donald M. "Chapter 144: Atopic Dermatitis (Atopic Eczema)." Nelson Textbook of Pediatrics. 18th ed. Ed. Robert M. Kliegman et al. Philadelphia: Saunders Elsevier, 2007.
Prescott, Susan L. and Bengt Björkstén. "Probiotics for the Prevention or Treatment of Allergic Diseases." Journal of Allergy and Clinical Immunology. Aug. 2007. 120(1): 255-62.