What Are Risk Factors for Atopic Dermatitis?
Atopic dermatitis, or atopic eczema, is a common skin condition, affecting up to 25% of children and 2-3% of adults.1 There are several factors that have been identified that increase a person’s risk of developing atopic dermatitis (AD), including:
- Having a family history of atopic dermatitis or other atopy (atopy refers to the genetic tendency to developing allergic diseases, like asthma or seasonal allergies)
- Having a personal history of atopy
- Where a person lives
- Mother’s age at child’s birth
- Socioeconomic status
Family history of atopic dermatitis
The majority of people with AD (approximately 70%) have someone in their family with the condition. An individual’s chances of developing AD are two to three-fold higher in children who have a parent with AD. If both parents have AD, the child’s chances of developing the skin condition increase to three to five-fold. Experts believe that the family history is closely related to genetic mutations in the FLG gene, which encodes the protein filaggrin.
Filaggrin gene mutations
Filaggrin plays important roles in the skin, including forming a healthy barrier and contributing to the normal moisture in the skin. However, the genetic mutations with FLG do not explain all cases of AD, as a significant number of people with AD have no known FLG mutations, and some people with mutations never develop AD.
Continued research for genetic risk factors
The genetic causes for AD remain an active area of investigation for researchers, and recent large-scale studies have identified potentially important roles other genes may play in skin barrier function and the immune system.1,2
Family history of asthma or hay fever
Geography increases risk
Living in urban areas (cities) appears to increase the risk of AD, although research has yet to uncover what in the environments of urban areas contributes to the cause of AD. Living in a developed country also seems to increase the risk of AD, and colder climates with low ambient humidity also increase a person’s risk of developing the condition.1,3
Some research has found that being female puts a person at a slightly higher risk for developing AD, however, other research has failed to find that being female or male increases a person’s risk of developing AD.1,3
Mother’s age at child’s birth
Children born to mothers who are later in their childbearing years are more likely to develop AD.3
Some studies have found that AD appears to be more common in higher socioeconomic groups, but other studies have failed to confirm this. It does seem that a higher level of parental education is associated with more cases of AD, and a higher level of education may account for a higher socioeconomic level.1
Factors that may lessen the risk of eczema
Research into the development of AD has found that there are some factors that may provide a protective effect or prevent AD. These factors are related to the normal exposure to germs and pathogens, which help build a child’s immune system. The hygiene hypothesis is that too much hygiene, including an increased use of antibiotics, may explain the higher incidence of AD in developed countries.
Factors that seem to have a protective effect against AD include:
- Application of emollients (a type of moisturizer) daily beginning early in life
- Attending day care in the first two years of life (due to the potential for exposure to many more pathogens in the day care environment)
- Exposure to farm animals, both during pregnancy and after birth
- Exposure to household pets (some research has shown dogs are beneficial while other research findings show that cats are beneficial; other research has failed to confirm these findings)1,4,5