What Is Atopic Dermatitis?
Atopic dermatitis is a chronic (long-lasting) disease that affects the skin. It is not contagious; it cannot be passed from one person to another. The word “dermatitis” means inflammation of the skin. “Atopic” refers to a group of diseases in which there is often an inherited tendency to develop other allergic conditions, such as asthma and hay fever. In atopic dermatitis, the skin becomes extremely itchy. Scratching leads to redness, swelling, cracking, “weeping” clear fluid, and finally, crusting and scaling. In most cases, there are periods of time when the disease is worse (called exacerbations or flares) followed by periods when the skin improves or clears up entirely (called remissions). As some children with atopic dermatitis grow older, their skin disease improves or disappears altogether, although their skin often remains dry and easily irritated. In others, atopic dermatitis continues to be a significant problem in adulthood.
Causes 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. In most people, atopic dermatitis is caused by a genetic dysfunction in the outermost layer of the skin (the epidermis). The epidermis is the first line of defense between the body and the environment. When the epidermis is intact, it keeps environmental irritants, allergens, and microbes from entering the body.
Symptoms of Atopic Dermatitis
Most people with eczema develop their first symptoms before age five. Intense itching of the skin, patches of redness, small bumps, and skin flaking are common. Scratching can cause additional skin inflammation, which can further worsen the itching. The itchiness may be more noticeable at nighttime. Features of eczema vary from one individual to another, and can change over time. Although eczema is usually confined to specific areas of the body, it may affect multiple areas in severe cases:
●In infants, there may be red, scaly, and crusted areas on the front of the arms and legs, cheeks, or scalp. The diaper area is not usually affected.
●In children and adults, eczema commonly affects the back of the neck, the elbow creases, and the backs of the knees picture (left). Other affected areas may include the face, wrists, and forearms (picture right). The skin may become thickened and darkened, or even scarred, from repeated scratching.
Skin Features Associated With Atopic Dermatitis
- Atopic pleat (Dennie-Morgan fold)—an extra fold of skin that develops under the eye
- Cheilitis—inflammation of the skin on and around the lips
- Hyperlinear palms—increased number of skin creases on the palms
- Hyperpigmented eyelids—eyelids that have become darker in color from inflammation or hay fever
- Ichthyosis—dry, rectangular scales on the skin
- Keratosis pilaris—small, rough bumps, generally on the face, upper arms, and thighs
- Lichenification—thick, leathery skin resulting from constant scratching and rubbing
- Papules—small raised bumps that may open when scratched and become crusty and infected
- Urticaria—hives (red, raised bumps) that may occur after exposure to an allergen, at the beginning of flares, or after exercise or a hot bath.
Stages of Atopic Dermatitis
When atopic dermatitis occurs during infancy and childhood, it affects each child differently in terms of both onset and severity of symptoms. In infants, atopic dermatitis typically begins around 6 to 12 weeks of age. It may first appear around the cheeks and chin as a patchy facial rash, which can progress to red, scaling, oozing skin. The skin may become infected. Once the infant becomes more mobile and begins crawling, exposed areas, such as the inner and outer parts of the arms and legs, may also be affected. An infant with atopic dermatitis may be restless and irritable because of the itching and discomfort of the disease.
In childhood, the rash tends to occur behind the knees and inside the elbows; on the sides of the neck; around the mouth; and on the wrists, ankles, and hands. Often, the rash begins with papules that become hard and scaly when scratched. The skin around the lips may be inflamed, and constant licking of the area may lead to small, painful cracks in the skin around the mouth.
In some children, the disease goes into remission for a long time, only to come back at the onset of puberty when hormones, stress, and the use of irritating skin care products or cosmetics may cause the disease to flare.
Factors That Make Atopic Dermatitis Worse
Many factors or conditions can make symptoms of atopic dermatitis worse, further triggering the already overactive immune system, aggravating the itch-scratch cycle, and increasing damage to the skin. These factors can be broken down into two main categories: irritants and allergens. Emotional factors and some infections and illnesses can also influence atopic dermatitis.
Irritants are substances that directly affect the skin and, when present in high enough concentrations with long enough contact, cause the skin to become red and itchy or to burn. Frequent wetting and drying of the skin may affect the skin barrier function. Also, wool or synthetic fibers and rough or poorly fitting clothing can rub the skin, trigger inflammation, and cause the itch-scratch cycle to begin. Soaps and detergents may have a drying effect and worsen itching, and some perfumes and cosmetics may irritate the skin. Exposure to certain substances, such as solvents, dust, or sand, may also make the condition worse. Cigarette smoke may irritate the eyelids.
Allergens are substances from foods, plants, animals, or the air that inflame the skin because the immune system overreacts to the substance. Inflammation occurs even when the person is exposed to small amounts of the substance for a limited time. Although it is known that allergens in the air, such as dust mites, pollens, molds, and dander from animal hair or skin, may worsen the symptoms of atopic dermatitis in some people, scientists aren’t certain whether inhaling these allergens or their actual penetration of the skin causes the problems. When people with atopic dermatitis come into contact with an irritant or allergen they are sensitive to, inflammation producing cells become active. These cells release chemicals that cause itching and redness. As the person responds by scratching and rubbing the skin, further damage occurs.
- Wool or synthetic fibers
- Soaps and detergents
- Some perfumes and cosmetics
- Substances such as chlorine, mineral oil, or solvents
- Dust or sand
- Cigarette smoke.
Children with atopic disease tend to have a higher prevalence of food allergy than those in the general population. An allergic reaction to food can cause skin inflammation (generally an itchy red rash), gastrointestinal symptoms (abdominal pain, vomiting, diarrhea), and/or upper respiratory tract symptoms (congestion, sneezing, and wheezing). The most common allergenic (allergy-causing) foods are eggs, milk, peanuts, wheat, soy, tree nuts, shellfish, and fish.
In addition to irritants and allergens, emotional factors, skin infections, and temperature and climate play a role in atopic dermatitis. Although the disease itself is not caused by emotional factors, it can be made worse by stress, anger, and frustration. Interpersonal problems or major life changes, such as divorce, job changes, or the death of a loved one, can also make the disease worse.
Bathing without proper moisturizing afterward is a common factor that triggers a flare of atopic dermatitis. The low humidity of winter or the dry year-round climate of some geographic areas can make the disease worse, as can overheated indoor areas and long or hot baths and showers. Alternately sweating and chilling can trigger a flare in some people. Bacterial infections can also trigger or increase the severity of atopic dermatitis. If a patient experiences a sudden flare of illness, the doctor may check for infection.
Treatment of Atopic Dermatitis
Treatment is more effective when a partnership develops that includes the patient, family members, and doctor. The doctor will suggest a treatment plan based on the patient’s age, symptoms, and general health. The patient or family member providing care plays a large role in the success of the treatment plan by carefully following the doctor’s instructions and paying attention to what is or is not helpful. Most patients will notice improvement with proper skin care and lifestyle changes.
The two main goals in treating atopic dermatitis are healing the skin and preventing flares. It is important for the patient and family members to note any changes in the skin’s condition in response to treatment, and to be persistent in identifying the treatment that seems to work best.
Medications: A variety of medications are used to treat atopic dermatitis.
Corticosteroid creams and ointments have been used for many years to treat atopic dermatitis and other autoimmune diseases affecting the skin.
When topical corticosteroids are not effective, the doctor may prescribe a systemic corticosteroid, which is taken by mouth or injected instead of being applied directly to the skin. Typically, these medications are used only in resistant cases and only given for short periods of time.
Antibiotics to treat skin infections may necessary. If viral or fungal infections are present, the doctor may also prescribe specific medications to treat those infections.
Certain antihistamines that cause drowsiness can reduce nighttime scratching and allow more restful sleep when taken at bedtime. This effect can be particularly helpful for patients whose nighttime scratching makes the disease worse.
Topical calcineurin inhibitors decrease inflammation in the skin and help prevent flares.
Barrier repair moisturizers reduce water loss and work to rebuild the skin.
Phototherapy: Use of ultraviolet A or B light waves, alone or combined, can be an effective treatment for mild to moderate dermatitis. If the doctor thinks that phototherapy may be useful to treat the symptoms of atopic dermatitis, he or she will use the minimum exposure necessary and monitor the skin carefully.
Treating Atopic Dermatitis in Infants and Children
- Give lukewarm baths.
- Apply lubricant immediately following the bath.
- Keep child’s fingernails filed short.
- Select soft cotton fabrics when choosing clothing.
- Consider using sedating antihistamines to promote sleep and reduce scratching at night.
- Keep the child cool; avoid situations where overheating occurs.
- Learn to recognize skin infections and seek treatment promptly.
- Attempt to distract the child with activities to keep him or her from scratching.
- Identify and remove irritants and allergens.
Skin care: Healing the skin and keeping it healthy are important to prevent further damage and enhance quality of life. Developing and sticking with a daily skin care routine is critical to preventing flares.
A lukewarm bath helps to cleanse and moisturize the skin without drying it excessively. Because soaps can be drying to the skin, the doctor may recommend use of a mild bar soap or nonsoap cleanser. Bath oils are not usually helpful.
After bathing, a person should air-dry the skin, or pat it dry gently (avoiding rubbing or brisk drying), and then apply a moisturizer to seal in the water that has been absorbed into the skin during bathing. A moisturizer increases the rate of healing and establishes a barrier against further drying and irritation. Lotions that have a high water or alcohol content evaporate more quickly, and alcohol may cause stinging. Therefore, they generally are not the best choice. Creams and ointments work better at healing the skin.
Another key to protecting and restoring the skin is taking steps to avoid repeated skin infections. Signs of skin infection include tiny pustules (pus-filled bumps), oozing cracks or sores, or crusty yellow blisters. If symptoms of a skin infection develop, the doctor should be consulted and treatment should begin as soon as possible.
Protection from allergen exposure: The doctor may suggest reducing exposure to a suspected allergen. For example, the presence of the house dust mite can be limited by encasing mattresses and pillows in special dust-proof covers, frequently washing bedding in hot water, and removing carpeting. However, there is no way to completely rid the environment of airborne allergens.
Changing the diet may not always relieve symptoms of atopic dermatitis. A change may be helpful, however, when the medical history, laboratory studies, and specific symptoms strongly suggest a food allergy. It is up to the patient and his or her family and physician to decide whether the dietary restrictions are appropriate.