Atopic Dermatitis (Eczema)

What causes atopic dermatitis

Atopic dermatitis results from several factors acting together:

• A leaky skin barrier: many people have variants in the filaggrin gene, which helps build the outer skin layer. The skin loses water easily and lets irritants and allergens in.
• An overactive immune response: type 2 inflammation (involving IL-4, IL-13 and IL-31) drives redness and itch.
• Skin microbiome changes: Staphylococcus aureus is more common on eczema skin and worsens flares.
• Genetics: a parent with eczema, asthma or hay fever raises a child's risk.
• Environment: urban living, cold, dry climates and hard water are associated with higher rates.

"Atopic" refers to a tendency to allergic conditions. Many children with atopic dermatitis go on to develop food allergy, asthma or allergic rhinitis, a pattern called the atopic march. Allergies can trigger flares, but they are rarely the underlying cause.

Atopic dermatitis vs eczema

Eczema is a family of conditions that cause itchy, inflamed skin. Atopic dermatitis is the most common type. Others include contact dermatitis, dyshidrotic eczema, nummular eczema and seborrheic dermatitis. In everyday use, "eczema" usually means atopic dermatitis.

Symptoms by age

Common features at any age:

• intense itch, often worse at night
• dry skin everywhere, not only on patches
• red, inflamed patches; on darker skin, inflammation may look brown, purple or gray rather than red
• thickened, leathery skin from scratching
• small bumps, oozing and crusting during flares
• color changes after flares that fade over months

Common triggers

• Irritants: soaps, bubble baths, fragranced products, detergents, wool and synthetic fabrics.
• Climate: cold, dry winter air; heat and sweating.
• Infections: Staph aureus, herpes simplex, and common viral illnesses.
• Allergens: dust mites, pet dander, pollen; foods in some young children.
• Stress and poor sleep.
• Hormonal changes: pregnancy and the menstrual cycle in some women.

Diagnosis

Atopic dermatitis is diagnosed from its appearance, location, itch and history, usually by a primary care doctor, pediatrician or dermatologist. Tests are not needed in most cases. Doctors may:

• swab infected skin
• arrange patch testing if contact allergy is suspected
• consider allergy testing only when the history suggests an immediate food or environmental allergy; positive blood or skin tests without symptoms often lead to unnecessary food avoidance
• take a skin biopsy rarely, to rule out other conditions

Treatment

Daily skin care (the foundation)

• Moisturize at least twice a day and after every bath, using thick fragrance-free creams or ointments. Use generous amounts; adults may need roughly 250 to 500 g (about 9 to 18 oz) a week during bad periods.
• Bathe briefly in lukewarm water with a soap-free cleanser, then pat dry and moisturize within 3 minutes.
• Dilute bleach baths, as advised by a doctor, can reduce bacteria and flares in some people.
• Wet wrap therapy for severe flares: damp bandages over moisturizer and medicine.

Anti-inflammatory creams

• Topical corticosteroids: the mainstay for flares. Strength depends on the body area and severity. Used correctly, they are safe; mild steroids on the face and stronger ones on thick skin, for short courses. Under-treatment from "steroid phobia" is more common than side effects.
• Calcineurin inhibitors (tacrolimus ointment, pimecrolimus cream): steroid-free; useful on the face, eyelids and skin folds.
• Other non-steroid creams: crisaborole, ruxolitinib cream, and newer options such as roflumilast and tapinarof creams.
• Proactive treatment: applying anti-inflammatory cream twice weekly to areas that often flare helps prevent relapses.

Treatments for moderate to severe disease

• Phototherapy: narrowband UVB light, 2 to 3 times a week.
• Biologic injections: dupilumab, tralokinumab and lebrikizumab block specific inflammatory signals. Dupilumab is approved from 6 months of age.
• Oral JAK inhibitors: upadacitinib and abrocitinib work quickly but need blood test monitoring.
• Traditional immunosuppressants: cyclosporine, methotrexate, and others.

Controlling itch and infection

• Keep nails short; use cotton gloves at night for young children.
• Oral antihistamines do not relieve eczema itch much, though sedating ones may help sleep during flares.
• Antibiotics for confirmed bacterial infection; antivirals for eczema herpeticum.

Complications

• Skin infections: bacterial (Staph), viral (eczema herpeticum, molluscum), and fungal.
• Sleep disruption, affecting mood, concentration and school performance.
• Eye problems: eyelid eczema, conjunctivitis, and rarely keratoconus or cataracts in severe disease.
• Anxiety and depression.
• Hand eczema affecting work, especially in wet jobs.

Outlook

Atopic dermatitis tends to improve with age. Many children have much milder disease or clear by adolescence, although the skin often stays sensitive and dry. Some people have lifelong eczema, and some develop it for the first time as adults. With modern treatments, almost everyone can achieve good control.

Prevention

There is no guaranteed way to prevent atopic dermatitis. In babies with a high risk of food allergy, early introduction of peanut and egg, as advised by a pediatrician, lowers the risk of food allergy. Avoiding known triggers and daily moisturizing reduce flares.

Frequently asked questions

What triggers atopic dermatitis flares?

Common triggers are soaps and fragranced products, dry winter air, heat and sweat, wool clothing, skin infections, stress, and allergens such as dust mites, pet dander and pollen. Food triggers are mainly a concern in some infants and young children with moderate to severe eczema.

Is atopic dermatitis contagious?

No. Atopic dermatitis cannot be passed to other people. However, eczema skin is more prone to infections such as impetigo or herpes, which can be contagious, so oozing, crusted or blistering areas should be seen by a doctor.

What is the best treatment for atopic dermatitis?

Daily moisturizing and gentle skin care are the base for everyone. Flares are treated with topical steroids or non-steroid creams such as tacrolimus. Moderate to severe eczema may need phototherapy, biologic injections such as dupilumab, or JAK inhibitor tablets.

Will my child grow out of eczema?

Many children improve significantly or clear completely by their teens, though their skin may remain dry and sensitive. Children with severe eczema or early-onset disease are more likely to have symptoms into adulthood. Good control now reduces complications.

Are steroid creams safe for eczema?

Yes, when used as directed. The right strength for the right area, for the recommended time, rarely causes problems. Skin thinning and stretch marks mainly happen with strong steroids used for long periods on thin skin. Ask your doctor how much to use and for how long.