Eczema and Allergic Disease: What’s the connection?

More than a quarter of those affected with food allergies are diagnosed with atopic dermatitis (AD) also known as eczema which can range from mild to severe forms of itchy rash, blisters, and dry skin. Eczema often occurs around the face, inside elbows, in the back of knees, arms, and hands. Usually atopic dermatitis lasts a lifetime and is deeply rooted in a family history of allergy.

The biological basis of atopic dermatitis is caused by a loss-of-function mutation in Exon 3  of the filaggrin (FLG) gene resulting in the absence of filaggrin.

Filaggrin is an important protein in the epidermis that acts to stabilize the stratum corneum (SC) layer by organizing the keratin into bundles which contribute to its strength and integrity. Breakdown of filaggrin also releases amino acids and organic molecules that form natural moisturizing factors (NMF) to keep it hydrated and moisturized. Upon the degradation of filaggrin, the epidermis becomes acidic which gives the skin an anti-microbial effect and allows for ceramide metabolism.

Therefore without the presence of filaggrin, AD patients are more prone to bacterial invasion because it loses its acidity due to an increase in pH which can contribute to infection and inflammation. Additionally,  AD patients have very few natural moisturizing factors and ceramides which contribute to dry skin, and disorganized keratin filaments causing epidermal fragility.

Recent studies have shown that FLG mutations increase the risk for asthma and allergic rhinitis (hay fever) as well as food sensitization. Although it is not entirely known that FLG mutations is significantly associated with food allergy, more research needs to be done to determine if other factors may be involved in the conversion of food sensitization to allergy.

If your child has symptoms of eczema, consult your doctor for possible treatment options such as specific topical medication and/or moisturizers to reduce inflammation and hydrate the skin.

For more information, visit:

http://www.foodallergy.org/page/eczema-and-food-allergies

http://www.jacionline.org/article/S0091-6749%2812%2901115-3/abstract

-Rachelle

Advertisements