Updated July 3, Accessed December 20, National Eczema Association website. Accessed December 21, Association of atopic dermatitis with being overweight and obese: a systematic review and metaanalysis. J Am Acad Dermatol. Exceptional Nurses Winchester Hospital was the first community hospital in the state to achieve Magnet designation, recognition for nursing excellence.
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Home Health Library. Risk factors include: There is a strong genetic component to atopic dermatitis, although the specific details of how it is inherited remain incompletely understood. Some allergens that may be associated with eczema include: Plant pollen Animal dander Household dust mites Molds Certain foods Atopic dermatitis can develop at any age, but the risk is greatest for infants and children.
Previous Next References Atopic dermatitis. Cancer Care. Emergency Services. Cesarean Birth. Imaging Services. High Blood Pressure. Laboratory Services. Maternity Services. Numerous other diseases and conditions can also cause an itchy rash — from scabies to viral infections like chickenpox to bacterial infections like impetigo. But unlike these other examples, eczema is not caused by tiny mites or microbes that can be passed from person to person.
Instead, atopic dermatitis is a chronic inflammatory skin condition, in which an immune system reaction causes symptoms to develop. The condition is associated with a wide range of potential risk factors , but its specific cause in any given person is unclear. The skin of people with eczema does not retain moisture well, causing it to become dry and lose its protective properties.
When this occurs, various symptoms can develop:. Rather than a single factor being behind the development of atopic dermatitis, research suggests that eczema is a complex condition involving genetics, skin barrier function, allergies , immune system dysfunction, and environmental factors.
What's more, the symptoms of atopic dermatitis typically arise from specific and varied triggers, including dry skin from weather changes, for example , a wide range of irritants like common cleaning products and fabrics, and stress.
The word "atopic" in atopic dermatitis indicates an association with allergies. Though the condition isn't always directly caused by an allergic reaction , it is commonly associated with other allergic conditions. In fact, atopic dermatitis is often the start of the so-called "atopic march," in which a person then develops food allergies , hay fever, and asthma. It's estimated that up to 60 percent of people with atopic dermatitis develop asthma or hay fever and up to 30 percent have food allergies.
As with other allergic disorders, atopic dermatitis tends to run in families. Having a parent with atopic dermatitis, hay fever, or asthma increases a person's risk of getting the skin condition. Brar notes, atopic dermatitis can also develop without a demonstrated family history for atopic conditions.
Research suggests that a number of genes are associated with the development of atopic dermatitis. One gene with the strongest association is FLG, which encodes a protein, called filaggrin , that is important for creating a strong skin barrier to keep water in and foreign substances out.
About 20 to 30 percent of people with atopic dermatitis have a mutated or altered FLG gene, compared with 8 to 10 percent of people without atopic dermatitis, according to the National Library of Medicine.
In very rare cases, atopic dermatitis may arise from the mutation of a single gene: CARD A mutation in this gene can result in abnormalities in certain immune system cells.
Some research suggests that boys are more likely than girls to develop atopic dermatitis during infancy, and this pattern switches in adolescence. Various other risk factors may also exist, though the data is still inconclusive. Specifically, these potential risk factors include:.
On the opposite side of things, some factors may be protective against atopic dermatitis. Others may include:. But food allergies go hand in hand with atopic dermatitis , thanks to the atopic march. About 50 to 70 percent of children with early onset atopic dermatitis have one or more allergies, mainly food allergies, the most common of which are cow's milk, hen's eggs, and peanuts. Some such disorders are Netherton syndrome ; immune dysregulation, polyendocrinopathy, enteropathy, X-linked IPEX syndrome; and severe dermatitis, multiple allergies, metabolic wasting SAM syndrome.
Atopic dermatitis is a common disorder that affects 10 to 20 percent of children and 5 to 10 percent of adults. The genetics of atopic dermatitis are not completely understood. Studies suggest that several genes can be involved in development of the condition. In very rare cases, atopic dermatitis is caused by inherited mutations in a single gene. One such gene is the CARD11 gene. The protein produced from this gene turns on signaling pathways involved in the development and function of immune system cells called lymphocytes.
These changes impair pathway signaling, and as a result, certain lymphocytes called T cells do not develop or function properly. The number of these cells is normal, but their response to foreign invaders such as bacteria and fungi is diminished. The T cell abnormalities lead to a weakened immune system and recurrent infections, which are common in people with CARD11 -associated atopic dermatitis. It is not clear how the immune dysfunction caused by CARD11 gene mutations leads to skin rashes and allergic disorders in affected individuals.
Atopic dermatitis is not initially caused by an allergic reaction, although sometimes substances that can cause allergic reactions allergens are thought to contribute to flare-ups of the rashes.
In contrast to rare cases caused by CARD11 gene mutations, most cases of atopic dermatitis are thought to occur due to a combination of genetic and environmental factors such as living with a pet. Several common genetic variations may be involved, each contributing only a small amount to the risk of developing atopic dermatitis. The strongest of these associations is with the FLG gene, which is altered in 20 to 30 percent of people with atopic dermatitis compared with 8 to 10 percent of the general population without atopic dermatitis.
The FLG gene provides instructions for making a protein called profilaggrin, which is important for the structure of the outermost layer of skin. Proteins derived from profilaggrin help create a strong barrier to keep in water and keep out foreign substances, including toxins, bacteria, and allergens. These proteins also are part of the skin's "natural moisturizing factor," which helps maintain hydration of the outermost layer of skin.
Variations in the FLG gene lead to production of an abnormally short profilaggrin protein that cannot be processed to produce the other profilaggrin-related proteins. The resulting shortage can impair the barrier function of the skin. Impairment of the skin's barrier function contributes to development of allergic disorders, including atopic dermatitis.
Research suggests that without a properly functioning barrier, allergens are able to get into the body through the skin, triggering a reaction. In addition, a lack of natural moisturizing factor allows excess water loss through the skin, which can lead to dry skin.
Variations in many other genes are likely associated with development of atopic dermatitis, although most of these genes have not been identified or definitively linked to the disorder.
Researchers suspect these genes are involved in the skin's barrier function or in the function of the immune system. However, not everyone with a mutation in FLG or another risk-associated gene develops atopic dermatitis; exposure to certain environmental factors also contributes to the development of the disorder. Studies suggest that these exposures trigger epigenetic changes to the DNA. They can affect gene activity and regulate the production of proteins, which may influence the development of allergies in susceptible individuals.
Syndromes with atopic dermatitis as one of several features are caused by mutations in other genes.
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