ATOPIC DERMATITIS

Atopic Dermatitis is a condition that causes itchy, inflamed skin. It typically affects the insides of the elbows, backs of the knees, and the face, but can cover most of the body. Atopic dermatitis falls into a category of diseases called atopic, a term originally used to describe the allergic conditions asthma and hay fever. People who live in urban areas and in climates with low humidity seem to be at an increased risk for developing atopic dermatitis.

Symptoms vary from person to person. The most common symptoms are dry, itchy skin; cracks behind the ears; and rashes on the cheeks, arms, and legs. The itchy feeling is an important factor in atopic dermatitis, because scratching and rubbing in response to itching worsen the skin inflammation characteristic of this disease. People with atopic dermatitis seem to be more sensitive to itching and feel the need to scratch longer in response. They develop what is referred to as “the itch-scratch cycle”: The extreme itchiness of the skin causes the person to scratch, which in turn worsens the itch, and so on. Itching is particularly a problem during sleep, when conscious control of scratching decreases and the absence of other outside stimuli makes the itchiness more noticeable.

The way the skin is affected by atopic dermatitis can be changed by patterns of scratching and resulting skin infections. Some people with the disease develop red, scaling skin where the immune system in the skin is becoming very activated. Others develop thick and leathery skin as a result of constant scratching and rubbing. This condition is called lichenification. Still others develop papules, or small raised bumps, on their skin. This can be confused with rosacea. When the papules are scratched, they may open and become crusty and infected. These conditions can also be found in people without atopic dermatitis or with other types of skin disorders.

Atopic dermatitis may also affect the skin around the eyes, the eyelids, and the eyebrows and lashes. Scratching and rubbing the eye area can cause the skin to change in appearance. Some people with atopic dermatitis develop an extra fold of skin under their eyes, called an atopic pleat or Dennie-Morgan fold. Other people may have hyper-pigmented eyelids, meaning that the skin on their eyelids darkens from inflammation or hay fever (allergic shiners). Patchy eyebrows and eyelashes may also result from scratching or rubbing.

Other symptoms of atopic dermatitis include a reddened face with paleness around the mouth, darkened circles under the eyes, and additional lines on the palms of the hands.The appearance of the rash may be very different from one person to another. Scratch marks are often seen, along with scaly dry skin. The skin may become infected and show yellow crusts or little, pinpoint, pus-containing bumps. The skin also may become thickened from long-term scratching and rubbing.

Inflammation results from too many reactive inflammatory cells in the skin. Research is seeking the reason why these cells over-react. Patients with Atopic dermatitis (or asthma or hay fever) are born with these over-reactive cells. When something triggers them, they don’t turn off as they should. We try to control Atopic dermatitis by preventing the trigger factors that turn on inflamed skin, or with anti-inflammatory therapies.

In childhood, the rash tends to occur behind the knees and inside the elbows; on the sides of the neck; 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. Severe cases of atopic dermatitis may affect growth, and the child may be shorter than average.

The condition may go into remission. The length of a remission varies, and it may last months or even years. In some children, the condition gets better 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 condition to flare.

The pattern in adults is similar to that seen in children; that is, the condition may be widespread or limited to a more restricted form. In some adults, only the hands or feet may be affected and become dry, itchy, red, and cracked. Sleep patterns and work performance may be affected, and long-term use of medications to treat the atopic dermatitis may cause complications. Adults with atopic dermatitis also have a predisposition toward irritant contact dermatitis, especially if they are in occupations involving frequent hand wetting or hand washing or exposure to chemicals. Some people develop a rash around their nipples. These localized symptoms are difficult to treat, and people often do not tell their doctor because of modesty or embarrassment. Adults may also develop cataracts that are difficult to detect because they cause no symptoms. Therefore, the doctor may recommend regular eye exams.

Common trigger factors include:

• Dry skin. The skin’s main function is to provide a barrier against dirt, germs and chemicals from the outside. We don’t notice this barrier unless it gets dry, and then it’s scaly, rough and tight. Dry skin is brittle — moist skin is soft and flexible. People with Atopic dermatitis have a defect in their skin and it won’t stay moist. It is especially bad in winter when the heat is on in the house and the humidity drops. Other things that dry the skin are too much bathing without proper moisturizing.
• Irritants are any of the substances outside the body that can cause burning, redness, itching or dryness of the skin.
• Emotional stress comes from many situations. People with Atopic dermatitis often react to stress by having red flushing and itching.
• Heat and sweating. Most people with atopic dermatitis notice that when they get hot, they itch. They have a type of prickly heat that doesn’t occur just in humid summertime but any time they sweat. It can happen from exercise, from too many warm bedclothes or rapid changes in temperature from cold to warm.
• Infections. Bacterial "staph" infections are the most common, especially on arms and legs. Such infections might be suspected if areas are weeping or crusted or if small "pus-bumps" are seen. Herpes infections (such as fever blisters or cold sores) and fungus (ringworm or athlete’s foot) can also trigger Atopic dermatitis. If some lesions look different, ask your doctor. If they turn out to be infected, they can be treated with antibiotics.
• Allergens. Allergens are materials such as pollen, pet dander, foods, or dust that cause allergic responses. Allergic diseases such as asthma and hay fever, which flare quickly, are easy to tie to allergens. Itching and hives appear soon after exposure to these airborne allergens and last only briefly.

Avoiding trigger factors:

• Keep the skin barrier intact. MOISTURIZE!
• Wear soft clothes that "breathe." Avoid fabrics of wool, nylon, or stiff material.
• If sweating causes itch, find ways to keep cooler:
• Reduce exertion, especially during times of flare.
• Layer clothing and adjust to temperature changes.
• Don’t overheat rooms, especially the bedroom.
• Use light bedclothes.
• When itching from sweating, dust, pollen or other exposures take a cooling shower or tub bath.
• Learn to recognize signs of infection and treat early.
• If you suspect food allergy, be systematic. Likely offenders are eggs, milk, peanuts, soy, wheat and seafood, but any food can do it. Keep a food diary. When the skin clears up, try the food. Watch for signs of itching or redness over the next two hours. Do not try a suspect food if it causes hives or face swelling
• Pet dander can be a problem. If you must have pets, keep them outside or at least off beds, rugs and furniture where the child plays. Dust mites collect in bedroom carpets and bedding. Simple control measures include coverings for pillows and mattresses, removing bedroom carpets and frequent washing of bedclothes in hot water.

Irritants are substances that cause burning, itching, or redness, such as solvents, industrial chemicals, detergents, fumes, tobacco smoke, paints, bleach, woolen fabrics, acidic foods, astringents and other alcohol-containing skin care products, and some soaps and fragrances. If an irritant is potent, or concentrated enough, it can irritate anyone’s skin, whether they have Atopic dermatitis or not.

Allergens are more subtle trigger factors. An allergen does not irritate, but may trigger a flare-up in those who have become allergic to it from prior exposure. Allergens are usually animal or vegetable proteins from foods, pollens, or pets.

When people with Atopic dermatitis are exposed to an irritant or allergen to which they are sensitive, inflammation-producing cells come into the skin. There, they release chemicals that cause itching and redness. Further damage occurs when the person scratches and rubs the affected area.

Food allergies can cause flare-ups. Since an allergic reaction to food (either by skin contact during food preparation or by eating the food) can trigger a flare-up, it is important to identify the trigger foods.

Many sufferers recognize a relationship between stressful occurrences in their lives and their flare-ups. Anger, frustration, and embarrassment all may cause flushing and itching. The resultant scratching can cascade into perpetuating dermatitis.

Extreme cold or hot temperatures, or sudden changes in the temperature, are poorly tolerated by persons with Atopic dermatitis. High humidity causes increased sweating and may result in prickly-heat-type symptoms. Low humidity dries the skin, especially during winter months when homes are heated. Unfortunately, humidifiers do not help much; the best protection against "winter itch" is regular application of a good moisturizer. While you can do little about the climate (and moving to a new climate is often not possible, anyway), you can try to keep your home environment comfortable. Keeping thermostats set low and wearing fewer bedclothes, to prevent night sweating, are two ways to combat the problem.

The only problem with exercise is that the resultant sweating generally causes itching. Layers of clothing can be removed to avoid overheating. Strenuous exercise is best avoided when a flare-up occurs.

The best line of defense is prevention, but flare-ups rarely can be avoided. Once inflammation begins, prompt treatment is needed. Bathing or wet compresses may ease the itch.

The skin of a person with atopic dermatitis loses too much moisture from the epidermal layer, allowing the skin to become very dry and reducing its protective abilities. In addition, the patient’s skin is very susceptible to recurring infections, such as staphylococcal and streptococcal bacterial skin infections and warts, herpes simplex, and molluscum contagiosum (skin disorders caused by a virus).

Currently, there is no test to diagnose atopic dermatitis and no single symptom or feature used to identify the disease. Each patient experiences a unique combination of symptoms, and the symptoms and severity of the disease may vary over time. The doctor will base his or her diagnosis on the symptoms the patient experiences and may need to see the patient several times to make an accurate diagnosis. It is important for the doctor to rule out other diseases and conditions that might cause skin irritation. In some cases, the family doctor or pediatrician may refer the patient to a dermatologist or allergist (allergy specialist) for further evaluation.