Understanding Atopic Dermatitis

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If you’ve had it, you know it: the dry, red, scaly, unbearably itchy skin condition called atopic dermatitis, or AD – the most common form of eczema.

You’re not alone: 18 million adults (7.2 percent) and 9.6 million children under the age of 18 (13 percent) have AD, according to the National Eczema Association. Among children, 3.2 million have moderate-to-severe symptoms.

Atopic dermatitis is a chronic inflammatory skin disease caused by an immune system reaction. It can cause red patches on the skin that itch, dry and scaly skin, thickened skin and open, oozing, crusty sores. AD symptoms often appear on the face, neck, hands, wrists, elbows, knees, ankles and feet.

Even if your skin appears clear, there may still be inflammation active underneath the surface, waiting to return with symptoms.

Atopic dermatitis often develops in early childhood – symptoms usually start within the first 5 years of life, often during the first 6 months.

Under the Skin

While its cause is unknown, doctors believe it results from allergic inflammation due to family history of the condition and environmental factors, including exposure to allergens and irritants.

The most common environmental allergens that trigger symptoms include pollen, mold, pet dander, dust mites and tobacco smoke. Food allergens are also common triggers, as are irritants such as wool or man-made fibers and soaps. (Contact dermatitis is a different form of eczema; it causes reactions to allergens and irritants caused by detergent, soap, scratchy clothes or nickel jewelry.)

Exposure to these allergens trigger immune cells to release histamines, cytokines and other chemicals to rid the allergen or irritant from the body. It signals the brain to move your hand to the itchy spot and scratch … and scratch. That only make it worse, resulting in an endless cycle.

Too much scratching can lead to infection if the surface of the skin is broken. Signs of infection include yellowish, crusty skin (often on top of the eczema), red, swollen bumps and pus-filled blisters.

Some people with atopic dermatitis may lack a specific type of protein, called filaggrin, in their skin. This protein serves as a protective barrier from allergens and bacteria. When filaggrin is lacking, it dries out and weakens the skin barrier. It’s also believed people with atopic dermatitis may have higher levels of Immunoglobulin E (IgE), antibodies produced by the immune system that can set off allergy symptoms.

On the Skin

Early diagnosis and treatment are essential to avoid skin complications and improve quality of life.

Treatment begins with avoiding or reducing exposures to known allergens and irritants. Then, keep your skin moisturized – with creams, lotions or ointments, especially during hot summers and dry winters, to lock moisture in your skin and protect against future rashes.

Moisturizers are the first-line therapy for treating atopic dermatitis. They work best if used at the first sign of itching; other treatments include antihistamines and corticosteroids that target inflammation. Topical immunomodulators, which regulate the local immune response of the skin, help reduce the redness and itching of inflamed skin. Antibiotics are used to treat skin infections.

New biologic medications treat moderate-to-severe atopic dermatitis. Biologics target cells and pathways that cause inflammation. Dupilumab is the first biologic approved by the U.S. Food and Drug Administration (FDA) – it is for adults and it’s prescribed only when topical treatments have not worked. Dupilumab is taken every two weeks by injection.

Doc Talk

Talk with your primary care doctor, an allergist or a dermatologist if you or your child develop symptoms of atopic dermatitis – especially if they are moderate or severe. Communication is as important as treatment in coping with AD; studies show the condition has a significant impact on mental health and quality of life.

With time and treatment, and as children mature, atopic dermatitis may go away – but it sometimes continues into adulthood. Between 10 and 30 percent of pediatric patients will experience symptoms in adulthood.

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