Atopic dermatitis

Definition

Atopic dermatitis (AD) is a chronic skin disorder associated with biochemical abnormalities in the patient's body tissues and immune system. It is characterized by inflammation, itching , weepy skin lesions, and an individual or family history of asthma , hay fever, food allergies , or similar allergic disorders. Atopic dermatitis is also known as infantile eczema or atopic eczema. The word atopic comes from atopy, which is derived from a Greek word that means "out of place." Atopy is a genetic predisposition to type I (immediate) hypersensitivity reactions to various environmental triggers. It includes bronchial asthma and food allergies as well as atopic dermatitis.

Description

AD varies in severity but in general is characterized by red, weeping, crusted patches of inflamed skin that itch constantly. The distribution of the skin lesions depends on the child's age. In infants, the skin lesions are usually found on the face, scalp, diaper area, body folds, hands, and feet, and tend to be exudative (oozing fluid that has escaped from blood vessels as a result of inflammation). Infants old enough to crawl may have patches of inflamed skin on the neck and trunk as well. In older children, the affected areas are usually located on the wrists, ankles, back of the neck, insides of the elbows, and the backs of the knees. The skin lesions in older children are more likely to be lichenified than exudative. Lichenification is the medical term for a leather- or bark-like thickening of the outermost layer of skin cells (the epidermis) as a result of long-term scratching or rubbing of itching lesions. In addition, the normal markings of the skin are exaggerated in lichenification.

The lesions of AD are accompanied by intense pruritus, which is the medical term for itching. Children with atopic dermatitis often have a lowered threshold of sensitivity to itching, which means that they feel itching sensations more intensely than children without the disorder. The pruritus often creates a vicious cycle of itching and scratching, which leads to more widespread rash, which leads to more itching. The child may scratch the affected skin only intermittently during the day, however. It is common for children with AD to do more scratching in the early evening and at night; moreover, disruptions of normal sleep patterns are common in these children.

Transmission

Atopic dermatitis is not contagious but may affect several members of the same family at the same time.

Demographics

Atopic dermatitis is a very common condition in the general population. According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), about 15 million people in the United States have one or more symptoms of the disease. It accounts for 15 to 20 percent of all visits to dermatologists (doctors who specialize in treating diseases of the skin). About 20 percent of infants develop symptoms of atopic dermatitis. Moreover, the proportion of people affected by AD is increasing; the American Academy of Allergy, Asthma, and Immunology (AAAAI) began a long-term study in 1999 that indicates that a larger percentage of children are affected by AD than was the case in the 1980s. This rise in prevalence is true of all developed countries, not just the United States and Canada. People who immigrate to Europe or North America from under-developed countries have increased rates of atopic dermatitis, which suggests that environmental factors play a role in the development or triggering of the disorder.

Atopic dermatitis begins early in life; about 65 percent of patients with AD develop symptoms during the first 12 months of life, with 90 percent showing symptoms before five years of age. The most common age for the onset of symptoms in infants is between six and 12 weeks of age. It is unusual for adults over the age of 30 to develop AD for the first time.

There is some disagreement among researchers with regard to race or ethnicity as risk factors for atopic dermatitis. Some studies indicate that all races and ethnic groups are equally at risk, while others suggest that Asians and Caucasians have slightly higher rates of AD than African Americans or Native Americans. Some skin lesions typical of AD may be more difficult to evaluate in African Americans because of the underlying skin pigmentation. With regard to sex, males and females appear to be equally at risk.

Atopic dermatitis is a major economic burden on families with children affected by the disorder. One researcher in Australia stated that the stresses on families with children diagnosed with moderate or severe AD are greater than the burdens on families with children with type 1 diabetes. These stresses include loss of sleep, loss of employment for the parents, time taken for direct care of the skin disorder, and the financial costs of treatment. The National Institutes of Health (NIH) estimates that atopic dermatitis costs U.S. health insurance companies more than $1 billion every year.

Causes and symptoms

Causes

The causes of atopic dermatitis were not completely understood as of 2004 but are thought to be a combination of genetic susceptibility, damaged skin barrier function, and abnormal responses of the child's immune system to environmental triggers. With regard to genetic factors, the disorder has been tentatively linked to loci on chromosomes 11 and 13. A child with one parent with AD has a 60 percent chance of developing the disorder; if both parents are affected, the risk rises to 80 percent. Nearly 40 percent of newly diagnosed children have at least one first-degree relative with atopic dermatitis.

In addition to genetic susceptibility, AD is the end result of a complex inflammatory process involving abnormalities in the child's skin and immune system. Some researchers have noted that the skin of people with AD contains lower levels of fatty acids, which may cause the skin to lose moisture more readily and become more sensitive to chemicals and other irritants. Others point to decreased production of a hormone in the immune system called interferon-gamma that ordinarily helps to regulate the body's response to allergens. People with AD may be hypersensitive to irritants because they have abnormally low levels of interferon-gamma in their systems.

About 80 to 90 percent of children with AD also have unusually high levels of an antibody called IgE in their blood. Antibodies are specialized proteins produced by the immune system that seek out and destroy bacteria, viruses, and other invaders. The high levels of IgE in the blood of AD patients are produced by hyperactive T helper 2 cells reacting against antigens in the environment. Although the role of increased IgE production in the development of atopic dermatitis was not fully understood as of 2004, measuring the level of this antibody in a sample of blood serum may be done to help distinguish AD from other skin diseases with similar symptoms.

Symptoms

The basic symptoms of AD have already been described. Dermatologists classify the lesions of AD into three basic categories:

• Acute lesions: These include extremely itchy reddened papules (small solid eruptions resembling pimples) and vesicles (small blister-like elevations in the skin surface that contain tissue fluid) over erythematous (reddened) skin. Acute lesions produce a watery exudate and are often accompanied by exfoliation (scaling or peeling of layers of skin) and erosion (destruction of the skin surface).
• Subacute lesions: These are characterized by reddening, peeling, and scaling but are less severe than acute lesions and do not produce an exudate.
• Chronic lesions: These are characterized by thickened plaques of skin, lichenification, and fibrous papules.

It is possible for a child or adolescent with chronic atopic dermatitis to have all three types of lesions at the same time.

Associated symptoms and disorders

Children and adolescents with AD frequently develop one or more of the following disorders or problems:

• Asthma: About 50 percent of children diagnosed with AD eventually develop asthma.
• Allergic rhinitis : Between 70 and 75 percent of children with AD eventually develop a nasal allergy. Allergic rhinitis , which is sometimes called atopic rhinitis, may be either seasonal (hay fever or rose fever) or nonseasonal (caused by dust, mold spores, pet dander, cigarette smoke, and other household allergens).
• Eye complications: These include such disorders as conjunctivitis (inflammation of the tissue that lines the eyelid), keratoconus (a cone-shaped distortion of the cornea of the eye), and cataracts. Although cataracts are usually associated with older adults, between 4 and 12 percent of children with AD develop rapidly maturing cataracts that may begin to interfere with vision as early as age 20. About 1 percent develop keratoconus.
• Ichthyosis, xerosis (dry skin), lichenification, and other skin abnormalities not caused by infections: Children with AD are likely to develop other skin problems.
• Secondary skin infections: Children and adolescents with AD frequently develop infections from bacteria that live on the skin and multiply when the child's scratching causes breaks or open sores in the skin. Most of these secondary infections are caused by Staphylococcus aureus and Streptococcus pyogenes.
• Psychosocial problems: Children with atopic dermatitis may withdraw socially if the lesions are extensive or otherwise noticeable. In addition, children with severe cases may have frequent absences from school. Adolescents may suffer depression or anxiety related to concerns about their appearance or the need to avoid participating in sports in order to minimize sweating.

When to call the doctor

Atopic dermatitis is rarely a medical emergency and can often be treated by the child's pediatrician. Parents should, however, consider consulting a dermatologist, allergist, or immunologist under any of the following circumstances:

• The child's AD has been diagnosed as severe. This classification means that 20 percent of the body's skin surface has been affected or 10 percent of the skin area in addition to involvement of the eyes, hands, and body folds.
• There is extensive exfoliation (peeling and scaling) of the skin.
• The child has eye complications.
• The child has recurrent secondary bacterial infections.
• The child is frequently absent from school, has developed psychosocial complications, or has impaired quality of life. In many cases the entire family's quality of life is affected by the stresses and frustrations of coping with the disease, and other family members' reactions may in turn upset the child with AD.
• The child has had to be hospitalized for treatment of the AD.
• The child has had to take more than one course of oral steroid drugs.
• The diagnosis is uncertain.

Diagnosis

History and physical examination

Diagnosis of atopic dermatitis begins with a history-taking and physical examination by the child's doctor. In the case of infants or very young children, the doctor will ask the parents for information about a family history of atopic disorders as well as information about the onset of the symptoms. The doctor will then examine the child's skin and assess the following factors:

• physical appearance of the lesions and their distribution on the child's body
• timing, which includes seasonal variations in the severity of the rash as well as its chronic or recurrent nature
• environmental factors, which includes foods as well as such common triggers of AD as dust, pet dander, household cleaning agents, plastics, nail polish remover, and other cosmetics or chemicals
• presence of such other conditions associated with AD as eye complications or bacterial infections of the skin

The doctor will ask older children and adolescents directly whether their skin lesions are affected by such factors as pets in the household; smoking ; using perfumes, shampoos, deodorants, or other personal care products; taking certain prescription medications; wearing wool or other rough-textured fabrics; using laundry detergents or fabric softeners; being exposed to extremes of temperature or humidity; athletic activity; emotional stress; and (in females past puberty ) hormonal changes related to menstruation .

There are no laboratory tests that can confirm the diagnosis of AD; in some cases, the doctor may need to examine the child more than once in order to distinguish between atopic and seborrheic dermatitis . In most cases, the doctor will make the diagnosis on the basis of criteria established by the AAAAI in the 1990s. To be considered atopic dermatitis, the child's symptoms must at total at least three major and three minor symptom criteria.

There are four major criteria for AD:

• pruritus
• typical form and distribution of skin lesions
• chronic or recurrent dermatitis
• a personal or family history of atopic disorders

There are about two dozen minor criteria for atopic dermatitis. The most common minor characteristics are early age of onset, food intolerance, wool intolerance, susceptibility to skin infections, immediate type I response to skin test, elevated total serum IgE, eczema of the nipples, xerosis or dry skin, dermatitis of the hands and feet, recurrent conjunctivitis, sensitivity to emotional stress, and ichthyosis.

Family practitioners often refer patients with AD to an allergist for consultation, particularly if the child has developed asthma or has acute reactions to foods.

Laboratory tests

In addition to a general physical examination, the doctor may order a blood test to look for the presence of elevated IgE levels in the blood serum. The doctor may also test tissue fluid or smears from the child's lesions to rule out skin parasites or infections that mimic atopic dermatitis, such as bacterial infections, scabies , or herpesvirus infections.

The doctor may recommend skin prick testing to determine whether certain specific substances or foods trigger the child's AD. These tests are usually given only to children with moderate or severe cases of atopic dermatitis. The child must discontinue taking oral antihistamine medications for one week before the tests and discontinue using topical steroid creams for two weeks. The test is performed by pricking the surface of the skin with a thin needle containing a small amount of a suspected allergen.

Treatment

The AAAAI recommends a four-part approach to the treatment of atopic dermatitis. Children with AD should take the following steps:

• Avoid foods or other factors that trigger symptoms, avoid such irritating fabrics as wool and synthetic fibers, wear 100 percent cotton underwear, trim fingernails short to minimize damage to the skin from scratching, keep the skin moist with proper use of emollient creams or oils after bathing, avoid the use of fabric softeners or scented detergents when laundering clothes and rinse clothes completely, and try to reduce emotional stress.
• Use appropriate medications as prescribed. The types of medications used vary depending on the severity of the child's symptoms and the presence of other infections. Most children are given both oral and topical (applied to the skin) medications. Topical medications include corticosteroid creams (Aristocort, Kenalog, Halog, Topicort, and many other brand names) and ointments containing immunomodulators, usually tacrolimus (Protopic) or pimecrolimus (Elidel). Corticosteroid creams are used to suppress inflammation, while the immunomodulator creams work by reducing the reactivity of the child's immune system. Although the corticosteroid creams have been used in both prescription-strength and over-the-counter (OTC) formulations for many years to treat AD, they may cause such side effects as thinning of the skin or stretch marks when used for long periods. They may also make skin infections worse. For these reasons, doctors recommend using the least powerful corticosteroid creams that control the symptoms. With regard to oral medications, antihistamines are often prescribed to stop itching at night so that the child can sleep. Oral or injected corticosteroids are sometimes used for short-term treatment of severe cases of AD that have not responded to topical medications; however, these drugs often have severe side effects, including stunted growth, thinning or weakening of the bones, high blood sugar levels, infections, and an increased risk of cataracts. Children with skin infections are usually given oral rather than topical antibiotics , most commonly penicillin or a cephalosporin.
• Regarding asthma or allergic rhinitis, the child should be evaluated for immunotherapy.
• The child's family and friends need to be educated about the condition, and the child needs to maintain a schedule of regular follow-ups. In addition to followup visits with the pediatrician and allergist, the child should have regular eye examinations as a safeguard against cataracts or other eye complications.

Other treatments that are sometimes used for atopic dermatitis are tar preparations and ultraviolet light therapy (phototherapy). Tar preparations are messy but were still as of 2004 considered useful for treating patients with chronic lichenified areas of skin. Phototherapy with ultraviolet A or B light waves, or a combination of both, may be used to treat older children or adolescents with mild or moderate atopic dermatitis; it is not suitable for infants or younger children. Some patients who do not respond to ultraviolet light alone benefit from a combination of phototherapy and an oral medication known as psoralen, which makes the skin more sensitive to the light. Phototherapy has two potential side effects from long-term use: premature aging of the skin and an increased risk of skin cancer .

Children or adolescents with AD must use extra care when bathing or showering. The doctor may recommend a non-soap skin cleanser, as standard bath soaps tend to dry and irritate the skin. If soaps are used, they should never be applied directly to broken or eroded areas of skin. The water should be lukewarm rather than hot, and the skin should be allowed to air-dry or be gently patted with a towel; brisk rubbing or the use of bath brushes must be avoided. After the skin has dried, the patient should apply a skin lubricant to seal moisture in the skin and create a barrier against further dryness or irritation.

Children with AD should also avoid unnecessary exposure to extremely hot, cold, moist, or dry outdoor environments. They should take care to avoid getting sunburned and should avoid participating in sports that involve physical contact or cause heavy perspiration.

Alternative treatment

There are a number of different complementary and alternative (CAM) approaches that have been used to treat atopic dermatitis, in part because the disorder is so widespread among children. In fact, infantile eczema is one of the most common conditions for which parents seek help from alternative practitioners. Most alternative therapies for atopic dermatitis fall into one of the following groups.

NATUROPATHY Naturopathy is a commonly used form of alternative treatment for AD; in one British study it was found effective for 19 out of 46 children in the subject group. Naturopaths favor food elimination diets as a way of managing AD, as well as lowering the child's overall intake of animal products. They recommend adding fish oil, flaxseed oil, or evening primrose oil to the child's diet to improve the condition of the skin, as many naturopaths believe that deficient intake of essential fatty acids is a major cause of AD. With regard to botanical products, a naturopath may suggest herbal preparations taken by mouth as well as topical creams made from herbs. Oral preparations may include extracts of hawthorn berry, blackthorn, or licorice root, while topical preparations to relieve itching typically include licorice or German chamomile. One German study found that a cream made with an extract of St. John's wort relieved the symptoms of AD better than a placebo, but the herbal preparation had not as of 2004 been compared to a standard corticosteroid cream.

HOMEOPATHY Homeopathy is the single most common CAM approach to atopic dermatitis in Europe, although it is frequently used in the United States as well. One German study followed a group of 2800 adults and 1130 children diagnosed with AD who were treated by homeopathic practitioners. The researchers found that over 600 different homeopathic remedies were recommended for the patients, although Sepia , Lycopodium, Sulphur, and Natrum muriaticum were the remedies most frequently prescribed. Most homeopathic practitioners in the United States as well as Europe consider AD a chronic condition that should be treated by constitutional homeopathic prescribing rather than by what is known as acute prescribing. In constitutional prescribing, the remedy is selected for long-term treatment of the patient's underlying susceptibility or constitutional weakness rather than short-term relief of present symptoms.

TRADITIONAL SYSTEMS OF MEDICINE According to Kenneth Pelletier, the former director of the alternative medicine program at Stanford University School of Medicine, both traditional Chinese remedies and Ayurvedic medicines benefit some people with atopic dermatitis. The British study of the use of CAM treatments in children with AD found that parents of Indian or Afro-Caribbean background were more likely to use these traditional approaches than Caucasian parents.

MIND/BODY APPROACHES Because flare-ups of AD are often related to increased emotional stress, some researchers have hypothesized that alternative approaches to lowering stress might help in treating the disorder. There is disagreement, however, about the effectiveness of such treatments as hypnosis or autogenic training. While some studies have reported that self-hypnosis, biofeedback, or autogenic training helped children with AD to manage their skin lesions with lower levels of steroid medications, other studies have reported that there is no conclusive evidence of the effectiveness of mind/body approaches in treating atopic dermatitis.

Nutritional concerns

Children and adolescents should avoid foods that trigger their AD. The most common offenders in flareups are peanuts and peanut butter, eggs and milk, seafood, soy, and chocolate. Long-term food elimination diets as a strategy for controlling AD are discussed below.

Children with moderate or severe AD often develop eroded areas or open cracks in the skin around the mouth from licking their lips or from allergic reactions to specific foods. They should apply a thin layer of petroleum jelly around the mouth before a meal to avoid irritation from citrus fruits, tomatoes, and other highly acidic foods.

Prognosis

As of the early 2000s, there is no cure for atopic dermatitis. People diagnosed with AD have highly individual combinations of symptoms that may vary greatly in severity over time. A significant percentage of children diagnosed with the condition, however, remain atopic into adulthood; one source states that 20 to 40 percent of children with infantile eczema continue to be affected, while NIAMS gives a figure of 60 percent. Some children included in these figures, however, outgrow the more severe forms of atopic dermatitis and suffer flare-ups in adult life only when they are exposed to high stress levels, chemical irritants, or other triggers in the environment. Other children may have only mild symptoms of AD until adolescence , when changes in hormone levels may cause a sudden worsening of symptoms.

Prevention

While atopic dermatitis in children cannot be completely prevented, NIAMS offers the following tips to parents as they try to help control the severity and frequency of flare-ups:

• Keep the child from scratching or rubbing the affected areas whenever possible.
• Avoid dressing the child in rough or scratchy fabrics and protect his or her skin from high levels of moisture.
• Keep the house at a cool, stable temperature with a consistent humidity level, using a humidifier during the heating season in colder climates.
• Quit smoking and do not allow others to smoke inside the house.
• Limit the child's exposure to dust, pollen, and animal dander. Some doctors recommend installing special filters in the house to remove dust and pollen from the air, removing carpets from the floors, or encasing mattresses and pillows with special covers to control dust mites.
• Recognize when the child is under stress and lower the stress level in the household if possible.

KEY TERMS

Allergen —A foreign substance that provokes an immune reaction or allergic response in some sensitive people but not in most others.

Atopy —A state that makes persons more likely to develop allergic reactions of any type, including the inflammation and airway narrowing typical of asthma.

Autogenic training —A form of self-hypnosis developed in Germany that appears to be beneficial to migraine sufferers.

Conjunctivitis —Inflammation of the conjunctiva, the mucous membrane covering the white part of the eye (sclera) and lining the inside of the eyelids also called pinkeye.

Dander —Loose scales shed from the fur or feathers of household pets and other animals. Dander can cause allergic reactions in susceptible people.

Dermatologist —A physician that specializes in diseases and disorders of the skin.

Eczema —A superficial type of inflammation of the skin that may be very itchy and weeping in the early stages; later, the affected skin becomes crusted, scaly, and thick.

Erythema —A diffuse red and inflamed area of the skin.

Exfoliate —To shed skin. In skin care, the term exfoliate describes the process of removing dead skin cells.

Exudation —Leakage of cells, proteins, and fluids through the blood vessel wall into the surrounding tissue.

Ichthyosis —A group of congenital skin disorders of keratinization characterized by dryness and scaling of the skin.

Keratin —A tough, nonwater-soluble protein found in the nails, hair, and the outermost layer of skin. Human hair is made up largely of keratin.

Keratoconus —An eye condition in which the central part of the cornea bulges outward, interfering with normal vision. Usually both eyes are affected.

Lichenification —Thickening of the outer layer of skin cells caused by prolonged scratching or rubbing and resulting in a leathery or bark-like appearance of the skin.

Papule —A solid, raised bump on the skin.

Pruritus —The symptom of itching or an uncontrollable sensation leading to the urge to scratch.

Rhinitis —Inflammation and swelling of the mucous membranes that line the nasal passages.

Scabies —A contagious parasitic skin disease caused by a tiny mite and characterized by intense itching.

Vesicle —A bump on the skin filled with fluid.

Xerosis —The medical term for dry skin. Many children diagnosed with atopic dermatitis have a history of xerosis even as newborns.

Nutritional concerns

The doctor may suggest a food challenge in order to identify a food or foods that may be triggering the child's skin rash. In a food challenge, a particular food is eliminated from the child's diet for a few weeks and then reintroduced. In some cases, a child with AD may benefit from a longer-term diet that eliminates problem foods entirely. In these cases, however, the child's height and weight should be carefully monitored to make sure that the diet is nutritionally adequate, and the diet itself should be reevaluated every four to six months. The doctor may recommend vitamin supplements or a consultation with a dietitian.

Parental concerns

Parental concerns about atopic dermatitis extend to the possible long-term consequences of the disorder as well as the child's present discomfort and sleeping problems. Depending on the severity and location of the skin rash, the child may withdraw from social activities to avoid teasing or resent restrictions on athletic or other outdoor activities. In addition to such possible complications of AD as eye disorders and skin infections, parents must also be attentive to signs of long-term side effects caused by medications or other forms of treatment for the AD. To cope with the impact of AD on other family members, parents may find counseling and support groups helpful. Because atopic dermatitis is so widespread in the general population, many support groups have been formed, particularly in the larger cities.

See also Allergic rhinitis; Allergies; Asthma.

Resources

BOOKS

"Atopic Dermatitis." Section 10, Chapter 111 in The Merck Manual of Diagnosis and Therapy, edited by Mark H. Beers and Robert Berkow. Whitehouse Station, NJ: Merck Research Laboratories, 2002.

"Hypersensitivity Disorders." Section 12, Chapter 148 in The Merck Manual of Diagnosis and Therapy, edited by Mark H. Beers and Robert Berkow. Whitehouse Station, NJ: Merck Research Laboratories, 2002.

Pelletier, Kenneth R. "CAM Therapies for Specific Conditions: Eczema." In The Best Alternative Medicine, Part II. New York: Simon & Schuster, 2002.

PERIODICALS

Ernst, E., et al. "Complementary/Alternative Medicine in Dermatology: Evidence-Assessed Efficacy of Two Diseases and Two Treatments." American Journal of Clinical Dermatology 3 (2002): 341–48.

Johnston, G. A., et al. "The Use of Complementary Medicine in Children with Atopic Dermatitis in Secondary Care in Leicester." British Journal of Dermatology 149 (September 2003): 566–71.

Kemp, A. S. "Cost of Illness of Atopic Dermatitis in Children: A Societal Perspective." Pharmacoeconomics 21 (2003): 105–13.

Leung, D. Y., et al. "New Insights into Atopic Dermatitis." Journal of Clinical Investigation 113 (March 2004): 651–57.

Ross, S. M. "An Integrative Approach to Eczema (Atopic Dermatitis)." Holistic Nursing Practice 17 (January-February 2003): 56–62.

Schempp, C. M., et al. "Topical Treatment of Atopic Dermatitis with St. John's Wort Cream: A Randomized, Placebo-Controlled, Double-Blind Half-Side Comparison." Phytomedicine 10 (2003), Supplement 4: 31–7.

ORGANIZATIONS

American Academy of Allergy, Asthma, and Immunology (AAAAI). 611 East Wells Street, Milwaukee, WI 53202. Web site: <www.aaaai.org>.

American Academy of Dermatology (AAD). PO Box 4014, Schaumburg, IL 60168–4014. Web site: <www.aad.org>.

National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). 1 AMS Circle, Bethesda, MD 20892–3675. Web site: <www.niams.nih.gov>.

WEB SITES

Krafchik, Bernice R. "Atopic Dermatitis." eMedicine, January 23, 2002. Available online at <www.emedicine.com/derm/topic38.htm> (accessed November 22, 2004).

OTHER

"Handout on Health: Atopic Dermatitis". NIH Publication No. 03–4272. National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). Bethesda, MD: NIAMS, 2003.

Rebecca Frey, PhD

Atopic Dermatitis

Definition

Eczema is a general term used to describe a variety of conditions that cause an itchy, inflamed skin rash. Atopic dermatitis, a form of eczema, is a non-contagious disorder characterized by chronically inflamed skin and sometimes intolerable itching.

Description

Atopic dermatitis refers to a wide range of diseases that are often associated with stress and allergic disorders that involve the respiratory system, like asthma and hay fever. Although atopic dermatitis can appear at any age, it is most common in children and young adults. Symptoms usually abate before the age of 25 and do not affect the patient's general health.

About one in ten babies develop a form of atopic dermatitis called infantile eczema. Characterized by skin that oozes and becomes encrusted, infantile eczema most often occurs on the face and scalp. The condition usually improves before the child's second birthday, and medical attention can keep symptoms in check until that time.

When atopic dermatitis develops after infancy, inflammation, blistering, oozing, and crusting are less pronounced. The patient's sores become dry, turn from red to brownish-gray, and skin may thicken and become scaly. In dark-skinned individuals, this condition can cause the complexion to lighten or darken. Itching associated with this condition is usually worst at night. It can be so intense that patients scratch until their sores bleed, sometimes causing scarring and infection.

Atopic dermatitis affects about 3% of the population of the United States, and about 80% of the people who have the condition have one or more relatives with the same condition or a similar one. Symptoms tend to be most severe in females. Atopic dermatitis can erupt on any part of the skin, and crusted, thickened patches on the fingers, palms, or the soles of the feet can last for years. In teenagers and young adults, atopic dermatitis often appears on one or more of the following areas:

• elbow creases
• backs of the knees
• ankles
• wrists
• face
• neck
• upper chest
• palms and between the fingers

Causes and symptoms

While allergic reactions often trigger atopic dermatitis, the condition is thought to be the result of an inherited over-active immune system or a genetic defect that causes the skin to lose abnormally large amounts of moisture. The condition can be aggravated by a cycle that develops in which the skin itches, the patient scratches, the condition worsens, the itching worsens, the patient scratches, etc. This cycle must be broken by relieving the itching to allow the skin time to heal. If the skin becomes broken, there is also a risk of developing skin infections which, if not recognized and treated promptly, can become more serious.

KEY TERMS

Corticosteroid— A steroid hormone produced by the adrenal gland or as a synthetic compound that reduces inflammation, redness, rashes, and irritation.

Dermatitis— Inflammation of the skin.

Symptoms of atopic dermatitis include the following:

• an itchy rash and dry, thickened skin on areas of the body where moisture can be trapped
• continual scratching
• chronic fatigue, caused when itching disrupts sleep

An individual is more at-risk for developing the condition if there is a personal or family history of atopic dermatitis, hay fever, asthma, or other allergies. Exposure to any of the following can cause a flare-up:

• hot or cold temperatures
• wool and synthetic fabrics
• detergents, fabric softeners, and chemicals
• use of drugs that suppress immune-system activity

Certain foods, such as peanuts, cow's milk, eggs, and fish, can trigger symptoms of atopic dermatitis. A small percentage of patients with atopic dermatitis find that their symptoms worsen after having been exposed to dust, feather pillows, rough-textured fabrics, or other materials to which dust adheres.

Diagnosis

Diagnosis of atopic dermatitis is usually based on the patient's symptoms and personal and family health history. Skin tests do not generally provide reliable information about this condition.

Treatment

Atopic dermatitis cannot be cured, but the severity and duration of symptoms can be controlled. A dermatologist should be consulted when symptoms first appear, and is likely to recommend warm baths to loosen encrusted skin, followed by applications of petroleum jelly or vegetable shortening to prevent the skin's natural moisture from escaping.

Externally applied (topical) steroids or preparations containing coal tar can relieve minor itching, but coal tar has an unpleasant odor, stains clothes, and may increase skin-cancer risk. Excessive use of steroid creams in young children can alter growth. Pregnant women should not use products that contain coal tar. Topical steroids can cause itching, burning, acne, permanent stretch marks, and thinning and spotting of the skin. Applying topical steroids to the area around the eyes can cause glaucoma.

Oral antihistamines, such as diphenhydramine (Benadryl), can relieve symptoms of allergy-related atopic dermatitis. More concentrated topical steroids are recommended for persistent symptoms. A mild tranquilizer may be prescribed to reduce stress and help the patient sleep, and antibiotics are used to treat secondary infections.

Cortisone ointments should be used sparingly, and strong preparations should never be applied to the face, groin, armpits, or rectal area. Regular medical monitoring is recommended for patients who use cortisone salves or lotions to control widespread symptoms. Oral cortisone may be prescribed if the patient does not respond to other treatments, but patients who take the medication for more than two weeks have a greater-than-average risk of developing severe symptoms when the treatment is discontinued.

Allergy shots rarely improve atopic dermatitis and sometimes aggravate the symptoms. Since food allergies may trigger atopic dermatitis, the doctor may suggest eliminating certain foods from the diet if other treatments prove ineffective.

If symptoms are extremely severe, ultraviolet light therapy may be prescribed, and a wet body wrap recommended to help the skin retain moisture. This technique, used most often with children, involves sleeping in a warm room while wearing wet pajamas under dry clothing, rain gear, or a nylon sweatsuit. The patient's face may be covered with wet gauze covered by elastic bandages, and his hands encased in wet socks covered by dry ones.

A physician should be notified if the condition is widespread or resists treatment, or the skin oozes, becomes encrusted, or smells, as this may indicate an infection.

Alternative treatment

Alternative therapies can sometimes bring relief or resolution of atopic dermatitis when conventional therapies are not helping. If the condition becomes increasingly widespread or infected, a physician should be consulted.

Helpful alternative treatments for atopic dermatitis may include:

• Taking regular brisk walks, followed by bathing in warm water sprinkled with essential oil of lavender (Lavandula officinalis ); lavender oil acts as a nerve relaxant for the whole body including the skin
• Supplementing the diet daily with zinc, fish oils, vitamin A, vitamin E, and evening primrose oil (Oenothera biennis )-all good sources of nutrients for the skin
• Reducing or eliminating red meat from the diet
• Eliminating or rotating potentially allergic foods such as cow's milk, peanuts, wheat, eggs, and soy
• Implementing stress reduction techniques in daily life.

Herbal therapies also can be helpful in treating atopic dermatitis. Western herbal remedies used in the treatment of this condition include burdock (Arctium lappa ) and Ruta (Ruta graveolens). Long-term herbal therapy requires monitoring and should be guided by an experienced practitioner.

Other alternative techniques that may be useful in the treatment of atopic dermatitis include:

• Acupressure (acupuncture without needles) to relieve tension that may trigger a flare
• Aromatherapy, using essential oils like lavender, thyme (Thymus vulgaris ), jasmine (Jasminum officinale ) and chamomile (Matricaria recutita ) in hot water, to add a soothing fragrance to the air
• Shiatsu massage and reflexology, performed by licensed practitioners, to alleviate symptoms by restoring the body's natural balance
• Homeopathy, which may temporarily worsen symptoms before relieving them, and should be supervised by a trained alternative healthcare professional
• Hydrotherapy, which uses water, ice, liquid, and steam, to stimulate the immune system
• Juice therapy to purify the liver and relieve bowel congestion
• Yoga to induce a sense of serenity.

Prognosis

Atopic dermatitis is unpredictable. Although symptoms occur less often with age and sometimes disappear altogether, they can recur without warning. Atopic dermatitis lowers resistance to infection and increases the risk of developing cataracts. Sixty percent of patients with atopic dermatitis will experience flares and remissions throughout their lives.

Prevention

Research has shown that babies weaned from breast milk before they are four months old are almost three times more likely than other babies to develop recurrent eczema. Feeding eggs or fish to a baby less than one year old can activate symptoms, and babies should be shielded from such irritants as mites, molds, pet hair, and smoke.

Possible ways to prevent flare-ups include the following:

• eliminate activities that cause sweating
• lubricate the skin frequently
• avoid wool, perfumes, fabric softeners, soaps that dry the skin, and other irritants
• avoid sudden temperature changes

A doctor should be notified whenever any of the following occurs:

• fever or relentless itching develop during a flare
• an unexplained rash develops in someone who has a personal or family history of eczema or asthma
• inflammation does not decrease after seven days of treatment with an over-the-counter preparation containing coal tar or steroids
• a yellow, tan, or brown crust or pus-filled blisters appear on top of an existing rash
• a person with active atopic dermatitis comes into contact with someone who has cold sores, genital herpes, or another viral skin disease

Resources

ORGANIZATIONS

American Academy of Dermatology. 930 N. Meacham Road, P.O. Box 4014, Schaumburg, IL 60168-4014. (847) 330-0230. Fax: (847) 330-0050. 〈http://www.aad.org〉.