How Common Is Atopic Dermatitis?

Statistics and epidemiology of atopic dermatitis

Atopic dermatitis (AD) is a common, chronic inflammatory skin condition that affects children and adults around the world. AD is also referred to as atopic eczema, and it is characterized by itchy, dry, scaly patches on the skin.

Epidemiology is the study of the incidence, distribution, and possible control of diseases and other factors related to health. Understanding the epidemiology of a health condition is important to understanding its impact on people, communities, and the healthcare system.

Who gets atopic dermatitis?

Atopic dermatitis is a commonly occurring condition with differing levels of severity. It occurs equally in males and females and affects an estimated 30 percent of people in the United States. Although atopic dermatitis may occur at any age, it most often begins in infancy and childhood.

Age

  • Ninety percent (90%) of all cases of AD are diagnosed in children before the age of 5 and 65% are diagnosed before the age of 1.1,2
  • Only 10% of cases are diagnosed after age 5, and only 5% of AD begins in adulthood.3
  • In the U.S., it is estimated that approximately 10.7% of children under the age of 18 have AD and that 17.8 million Americans have AD.5,6
  • While some people experience remission as they age, the majority of children with AD have persistent disease into their second decade of life or longer. One longitudinal study found that by age 20, 50% of people with AD reported at least one six-month period of remission7.
  • While most people who developed AD as a child outgrow it, between 10% and 30% of people continue to experience relapses into adulthood.8

Geography

  • There is a higher prevalence of eczema among people living in urban areas (cities).5
  • AD affects approximately 10-20% of children in developed countries.1

Race, ethnicity and gender

  • Eczema is more common in black and multi-race populations compared to whites.5
  • 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.3,8

Family history

  • 70% of people with AD have a family history of the condition.8
  • Children with a family history of AD, who are born to mothers later in their childbearing years, and who live in urban areas are more likely to develop AD.3,8

What is the cause and impact of atopic dermatitis?

The cause of atopic dermatitis is not known, but the disease seems to result from a combination of genetic (hereditary) and environmental factors. Atopic dermatitis is understood by some research to have features similar to an autoimmune condition. In autoimmune conditions like AD, the immune response is abnormally over-activated, causing a chronic inflammatory state that affects the skin.

  • AD is the most common form of eczema. (Eczema is a general term that refers to inflamed, itchy, rough skin.) Approximately 56.3% of all eczema cases are AD.9
  • While the exact causes of AD remains unclear, approximately 80% is believed to be due to genetic factors.1
  • Researchers have identified more than 40 mutations in the filaggrin gene (FLG) that have been associated with up to 50% of patients with moderate to severe AD. People who have mutations in FLG have a greater than threefold increased risk of developing AD.2
  • Research also shows that 80% of individuals with AD have symptoms and are using medication to treat their AD.7
  • Sleep is disrupted (due to the itch-scratch cycle of AD) in up to 60% of children with AD, increasing to 83% during times of exacerbated symptoms.8
  • About 30% of children with AD develop asthma, and 33% of children with moderate to severe AD have food allergies. AD also puts a person at a higher risk of developing hay fever, or allergic rhinitis.8,10,11
Emily Downward | June 2017
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