Atopic dermatitis

Atopic dermatitis is an inflammatory skin disease that causes redness, swelling and itching. It is more common in children, but can develop at any age. It is a chronic disease with periods of exacerbation and remission of variable duration. Sufferers may also have seasonal allergies or asthma.

Atopic dermatitis occurs in people whose skin does not have the ability to provide adequate protection against external agents, usually due to genetic causes. In these people, the skin is affected by various environmental factors, irritants and allergens.

The main risk factor associated with atopic dermatitis is a family or personal history of eczema, allergy, allergic rhinitis or asthma. In genetically predisposed individuals, there are a number of triggers for dermatitis:

  • Stress, which can cause an altered immune response.
  • Allergens, both food and airborne allergens.
  • Skin irritants, clothing made of wool or synthetic fibers, hot water or certain soaps and detergents.
  • Some microorganisms, especially S. aureus, a common colonizer of the skin of people with atopic dermatitis.

Atopic dermatitis is a chronic inflammatory skin disease with a high genetic influence. The heritability of atopic dermatitis has been estimated at 80% from twin studies, indicating that genetic factors account for most of the susceptibility. In an association study involving thousands of samples from various databases (FinnGen, Estonian Biobank, UK Biobank), 26 susceptibility loci associated with atopic dermatitis were identified. The authors estimate that these results could explain up to 30% of the heritability of the disease. The main risk factors identified include variants in filaggrin, encoded by the FLG gene and involved in the maintenance of the epidermal barrier, and genes involved in immune response, such as IL6.

Symptoms

Atopic dermatitis usually begins in childhood and may continue into adolescence and adulthood. Signs and symptoms of atopic dermatitis can vary from person to person and include the following:

  • Dry skin.
  • Itching, which can be very intense.
  • Reddish to grayish-brown spots that appear especially on the hands, feet, ankles, ankles, wrists, neck, chest, inner elbows or face.
  • Thickened, cracked and scaly skin.
  • Sensitive and inflamed skin from scratching.

Prevention

The following suggestions may prevent episodes of dermatitis and minimize symptoms should they occur:

  • Use of skin moisturizers at least twice a day.
  • Trying to avoid triggers that worsen the condition such as some foods, sweat, stress, soaps, detergents, etc.
  • Shorter baths or showers, avoiding very hot water.
  • Use of mild soaps.
  • Drying with care, avoiding strong friction.

Number of observed variants

13.5 million variants

Number of risk loci analyzed in the study

23 loci

Bibliography

Sliz E, Huilaja L, Pasanen A, et al. Uniting biobank resources reveals novel genetic pathways modulating susceptibility for atopic dermatitis. The Journal of Allergy and Clinical Immunology. 2022 Mar;149(3):1105-1112.e9

Mayo Clinic [March 2022]

National Health Service in England (NHS) [March 2022]

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