Diseases - Atopic Dermatitis - Part 2

 

Major and Minor Features of Atopic Dermatitis

Major Features

• Intense itching
  
• Characteristic rash in locations typical of the disease
  
• Chronic or repeatedly occurring symptoms
  
• Personal or family history of atopic disorders (eczema, hay fever, asthma)

Some Minor Features

• Early age of onset
  
• Dry, rough skin
  
• High levels of immunoglobulin E (IgE), an antibody, in the blood
  
• Ichthyosis
  
• Hyperlinear palms
  
• Keratosis pilaris
  
• Hand or foot dermatitis
  
• Cheilitis
  
• Nipple eczema
  
• Susceptibility to skin infection
  
• Positive allergy skin tests

What factors can aggravate atopic dermatitis?

Many factors or conditions can intensify the symptoms of atopic dermatitis, which can trigger the following cycle: further stimulating the already overactive immune system in the skin; aggravating the itch-scratch cycle; and increasing damage to the skin. These exacerbating elements can be broken down into two main categories; irritants and allergens. Emotional factors and some infections can also influence atopic dermatitis.

What are skin irritants in patients with atopic dermatitis?

Irritants are substances that directly affect the skin, and when used in high enough concentrations with long enough contact, cause the skin to become red and itchy or to burn. Specific irritants affect people with atopic dermatitis to different degrees. Over time, many patients and their families learn to identify the irritants that are most troublesome to them. For example, wool or synthetic fibers may affect some patients. Rough or poorly fitting clothing can rub the skin, trigger inflammation, and prompt the beginning of the itch- scratch cycle. Soaps and detergents may have a drying effect and worsen itching, and some perfumes and cosmetics may irritate the skin. Exposure to certain elements, such as chlorine, mineral oil, or solvents, or to irritants, such as dust or sand, may also aggravate the condition. Cigarette smoke may irritate the eyelids. Because irritants vary from one person to another, each person has to determine for himself or herself what substances or circumstances cause the disease to flare.

Common Irritants

• Wool or synthetic fibers
  
• Soaps and detergents
  
• Some perfumes and cosmetics
  
• Substances such as chlorine, mineral oil, or solvents
  
• Dust or sand
  
• Cigarette smoke

What are allergens?

Allergens are substances from foods, plants, or animals that provoke an overreaction of the immune system and cause inflammation (in this case, the skin). Inflammation can occur even when the person is exposed to small amounts of the allergen for a limited time. Some examples of allergens are pollen and dog or cat dander (tiny particles from the animal's skin or hair). When people with atopic dermatitis come into contact with an irritant or allergen to which they are sensitive, inflammation- producing cells permeate the skin from elsewhere in the body. These cells release chemicals that cause itching and redness. As the person scratches and rubs the skin in response, further damage occurs.

Certain foods act as allergens and may trigger atopic dermatitis or exacerbate it (cause it to become worse). Food allergens clearly play a role in a number of cases of atopic dermatitis, primarily in infants and children. An allergic reaction to food can cause skin inflammation (generally hives), gastrointestinal symptoms (vomiting, diarrhea), upper respiratory tract symptoms (congestion, sneezing), and wheezing. The most common allergy-causing (allergenic) foods are eggs, peanuts, milk, fish, soy products, and wheat. Although the data remain inconclusive, some studies suggest that mothers of children with a family history of atopic diseases should avoid eating commonly allergenic foods themselves during late pregnancy and (if breast feeding) while they are breast feeding the baby. Although not all researchers agree, most experts think that breast feeding the infant for at least 4 months may have a protective effect for the child.

If a food allergy is suspected, it may be helpful to keep a careful diary of everything the patient eats, noting any reactions. Identifying the food allergen may be difficult if the patient is also being exposed to other allergens, and may require supervision by an allergist. One helpful way to explore the possibility of a food allergy is to eliminate the suspected food and then, if improvement is noticed, reintroduce it into the diet under carefully controlled conditions. A two week trial is usually sufficient for each food. If the food being tested causes no symptoms after two weeks, a different food can be tested in like manner afterwards. Likewise, if the elimination of a food does not result in improvement after 2 weeks, other foods may be eliminated in turn.

Changing the diet of a person who has atopic dermatitis may not always relieve symptoms. A change may be helpful, however, when a patient's medical history and specific symptoms strongly suggest a food allergy. It is up to the patient and his or her family and physician to judge whether the dietary restrictions outweigh the impact of the disease itself. Restricted diets often are emotionally and financially difficult for patients and their families to follow. Unless properly monitored, diets with many restrictions can also contribute to nutritional problems in children.

What are aeroallergens?

Some allergens are called aeroallergens because they are present in the air. They may also play a role in atopic dermatitis. Common aeroallergens are dust mites, pollens, molds, and dander from animal hair or skin. These aeroallergens, particularly the house dust mite, may worsen the symptoms of atopic dermatitis in some people. Although some researchers think that aeroallergens are an important contributing factor to atopic dermatitis, others believe that they are insignificant. Scientists also don't understand the way in which aeroallergens affect the skin; whether the aeroallergen affects the person internally after being inhaled, or whether the aeroallergen actually penetrates the patient's skin.

No reliable test is available that determines whether a specific aeroallergen is an exacerbating factor in any given individual. If the doctor suspects that an aeroallergen is contributing to a patient's symptoms, the doctor may recommend ways to reduce exposure to the offending agents. 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 aeroallergens.

What other factors may play a role in atopic dermatitis?

In addition to irritants and allergens, other factors, such as emotional issues, temperature and climate, and skin infections can affect atopic dermatitis. Although the disease itself is not caused by emotional factors or personality, it can be exacerbated 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. Often, emotional stress seems to prompt a flare of the disease.

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 intensify the disease, as can overheated indoor areas and long or hot baths and showers. Alternately sweating and chilling can induce an attack in some people. Bacterial infections can also prompt or increase the severity of atopic dermatitis. If a patient experiences a sudden onset of illness, the doctor may check for a viral infection (such as herpes simplex) or fungal infection (such as ringworm or athlete's foot).

How is atopic dermatitis treated?

Treatment involves a partnership between the doctor and the patient and his or her family members. The doctor will suggest a treatment plan based on the patient's age, symptoms, and general health. The patient and family members play a large role in the success of the treatment plan by carefully following the doctor's instructions. Some of the primary components of treatment programs are described below. Most patients can be successfully managed with proper skin care and lifestyle changes and do not require the more intensive treatments discussed.

The doctor has three main goals in treating atopic dermatitis: healing the skin and keeping it healthy; preventing flares; and treating symptoms when they do occur. Much of caring for the skin involves developing skin care routines, identifying exacerbating factors, and avoiding circumstances that stimulate the skin's immune system and the itch-scratch cycle. It is important for the patient and family members to note any changes in skin condition in response to treatment, and to be persistent in identifying the most effective treatment strategy.

Skin Care: Healing the skin and keeping it healthy are of primary importance both in preventing further damage and enhancing the patient's quality of life. Developing and following a daily skin care routine is critical to preventing recurrent episodes of symptoms. Key factors are proper bathing and the application of lubricants, such as creams or ointments, within 3 minutes of bathing. People with atopic dermatitis should avoid hot or long (more than 10 to 15 minutes) baths and showers. A lukewarm bath helps to cleanse and moisturize the skin without drying it excessively. The doctor may recommend limited use of a mild bar soap or non-soap cleanser because soaps can be drying to the skin. Bath oils are not usually helpful.

Once the bath is finished, the patient should air-dry the skin, or pat it dry gently (avoiding rubbing or brisk drying), and apply a lubricant immediately. Lubrication restores the skin's moisture, increases the rate of healing, and establishes a barrier against further drying and irritation. Several kinds of lubricants can be used. Lotions generally are not the best choice because they have a high water or alcohol content and evaporate quickly. Creams and ointments work better at healing the skin. Tar preparations can be very helpful in healing very dry, lichenified areas. Whatever preparation is chosen, it should be as free of fragrances and chemicals as possible.

Another key to protecting and restoring the skin is taking steps to avoid repeated skin infections. Although it may not be possible to avoid infections altogether, the effects of an infection may be minimized if they are identified and treated early. Patients and their families should learn to recognize the signs of skin infections, including tiny pustules (pus-filled bumps) on the arms and legs, appearance of oozing areas, or crusty yellow blisters. If symptoms of a skin infection develop, the doctor should be consulted to begin treatment as soon as possible.

Treating Atopic Dermatitis in Infants and Children

• Give brief, lukewarm baths.
  
• Apply lubricant immediately following the bath.
  
• Keep child's fingernails filed short.
  
• Select soft cotton fabrics when choosing clothing.
  
• Consider using antihistamines to 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.

Medications and Phototherapy: If a recurrence of atopic dermatitis occurs, several methods can be used to treat the symptoms. With proper treatment, most symptoms can be brought under control within 3 weeks. If symptoms fail to respond, this may be due to a flare that is stronger than the medication can handle, a treatment program that is not fully effective for a particular individual, or the presence of trigger factors that were not addressed in the initial treatment program. These factors can include a reaction to a medication, infection, or emotional stress. Continued symptoms may also occur because the patient is not following the treatment program instructions.

Corticosteroid creams and ointments are the most frequently used treatment. Sometimes, over-the-counter preparations are used, but in many cases, the doctor will prescribe a stronger corticosteroid cream or ointment. Occasionally, the base used in certain brands of corticosteroid creams and ointments is irritating for a particular patient and a different brand is required. Side effects of repeated or long-term use of topical corticosteroids can include thinning of the skin, infections, growth suppression (in children), and stretch marks on the skin.

Tacrolimus (Protopic) and pimecrolimus (Elidel) ointments are powerful topical medicated creams (drugs that are applied to the skin) that is used for the treatment of atopic dermatitis. These new drugs are referred to as "immune modulators." They were first used internally to help patients with kidney and liver transplants avoid rejecting the organs they received. They work by suppressing the immune system. When these drugs are used externally to treat the skin, however, they do not weaken or change the body's immune system. Also, unlike topical steroids (cortisone creams), these new medications don't cause thinning of the skin and breaking of superficial blood vessels (atrophy).

Some treatments reduce specific symptoms of the disease. Antibiotics to treat skin infections may be applied directly to the skin in an ointment, but are usually more effective when taken by mouth in pill form. 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 aggravates the disease. If viral or fungal infections are present, the doctor may also prescribe medications to treat those infections.

Phototherapy is treatment with light that uses ultraviolet A or B light waves, or a combination of both. This treatment can be an effective treatment for mild to moderate dermatitis in older children (over 12 years old) and adults. Photochemotherapy, a combination of ultraviolet light therapy and a drug called psoralen, can also be used in cases that are resistant to phototherapy alone. Possible long-term side effects of this treatment include premature skin aging and skin cancer. If the doctor thinks that phototherapy may be useful in treating the symptoms of atopic dermatitis, he or she will use the minimum exposure n Glossary content Copyright © 1996-2002 MedicineNet, Inc. All rights reserved.