Atopic dermatitis is a disorder of the upper layers of the skin that usually begins in childhood. It typically affects those in families with a history of atopic dermatitis, allergic conditions or asthma. Scaly, itchy skin rashes are typical symptoms of the disorder, which is the most severe and longest-lasting form of dermatitis.

Atopic conditions occur in people who are overly sensitive to allergens in their environment. Though not technically caused by allergies, and not always triggered by an allergen, atopic dermatitis usually appears in infants and young children who already have allergies, or who are likely to develop them later.

The pattern of rash distribution is a distinguishing feature of atopic dermatitis, which is a common type of eczema (an inflammatory skin disease). Red, itchy patches usually start on the face, particularly the cheeks and chin. Over time, the face heals, but for some the rash will then appear on other parts of the body.

Atopic dermatitis is the most common form of eczema, and the terms are often used interchangeably. It is a skin disorder that primarily afflicts infants and children. For those who have the condition, the skin usually becomes extremely itchy. Excessive scratching then leads to redness, swelling and cracking of the skin. In some cases, the rash leaks fluid before crusting and becoming scaly. Bacterial infection brought on by incessant scratching is a common consequence of atopic dermatitis. Skin infection, particularly with Staphylococcus, is also a common trigger for exacerbations of atopic dermatitis.

The term “atopy” is used to describe people with a tendency for inflammation in the skin, as well as in the linings of the nose and lungs. Atopy often occurs in people with a family history of other allergic conditions, including asthma and allergic rhinitis.

There are two main forms of atopic dermatitis:

• Chronic, with symptoms lasting for long periods of time
  
  
• Episodic, with symptoms more likely to come and go in periodic flare-ups

The exact nature of the relationship between atopic dermatitis and allergies is unclear. However, it appears that those who are susceptible to atopic dermatitis have inherited a tendency to produce excessive antibodies such as immunoglobulin E (IgE). Some studies have found that those with atopic dermatitis have a low level of a cytokine (a type of protein) which is essential to the healthy functioning of the body’s immune system. In addition, these individuals tend to have high levels of other cytokines that trigger allergic reactions.

Atopic dermatitis usually begins shortly before children are 6 months of age (where it is often related to food allergies), and almost always before they are 5 years old. An estimated 20 percent of infants and young children develop atopic dermatitis, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases. In early childhood, more boys develop atopic dermatitis than girls. As children get older, this reverses.

For some children, atopic dermatitis improves or disappears as they get older. For other patients, the skin may stay dry and sensitive into adulthood. About 60 percent of people who develop atopic dermatitis as children continue to have one or more symptoms of the disease into adulthood.  

While the precise cause of atopic dermatitis is unknown, scientists believe a combination of genetics and environmental factors are responsible for the disease. Children are more likely to develop atopic dermatitis if one or both parents have a history of allergic conditions or asthma. According to the American Academy of Dermatology, only 20 percent of people with atopic dermatitis have no family members with the condition.

Although some children outgrow skin symptoms, nearly three-fourths of children with atopic dermatitis develop hay fever (allergic rhinitis) or asthma, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

Environmental factors can also bring on symptoms of atopic dermatitis in those who have inherited the atopic disease trait. People living in dry climates may be more likely to develop the condition. 

There may also be a relationship between food allergies and atopic dermatitis. Patients with atopic dermatitis should consult their physician about this possible link.

Factors that may trigger atopic dermatitis or make it worse include:

• Emotional stress
  
  
• Temperature changes and humidity extremes
  
  
• Bacterial skin infections
  
  
• Contact with skin irritants, such as wool clothing, soap, laundry detergents and cosmetics
  
  
• Sweating
  
  
• Bathing
  
  
• Dry skin

Atopic dermatitis tends to unfold in three stages, each of which has its own characteristic symptoms.  

• First phase: The initial period of atopic dermatitis symptoms usually begins within the first 6 months of a child's life (often on the cheeks and the folds behind the elbows and knees). Symptoms, which periodically flare up and worsen over time, include:
  
  
• • Itchy, dry, red skin
    
    
  • Small bumps on the cheeks, forehead or scalp
    
    
  • Rash that spreads to the arms and torso
    
    
  • Red, crusted lesions on the face, scalp, arms or legs
    
    
• Second phase: This middle phase usually occurs between ages 4 and 10. Symptoms include:
  
  
• • Circular, slightly raised, itchy and scaly eruptions in the bends of the knees and elbows; or, on the back of wrists and ankles
    
    
  • Rash that is less scaly and itchy than during the first phase
    
    
  • Extremely itchy and dry skin
    
    
  • Thickened, brownish areas of skin from intense scratching
    
    
• Third phase: In this final phase, symptoms gradually reduce and often subside by adulthood. Symptoms in this stage include:
  
  
• • Itchiness
    
    
  • Dry, scaly skin

Not all patients experience symptoms that follow this pattern. Some find significant improvement around age 5, only to see the condition return in puberty. Others will see flare-ups continue on and off through adulthood. In rare cases, atopic dermatitis will not appear for the first time until adulthood. In these cases, the rash tends to affect the hands, neck, face, genitals and the inside surfaces of knees and elbows.

Sometimes, atopic dermatitis will lead to bacterial infections in the skin. Symptoms of such an infection include:

• Red streaks extending from the infected area
  
  
• Pus or fluid discharge from the rash
  
  
• Honey-colored crusts on the skin
  
  
• Fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher with no other cause

There are many skin and eye conditions that are closely related to atopic dermatitis. Those who suffer from the condition need to be on guard for these associated disorders. Some can damage vision while others can be life-threatening.

An atopic dermatitis rash infected with the herpes simplex virus (which also causes cold sores and genital herpes) can lead to a condition known as eczema herpeticum. During this infection, the rash may blister, bleed and crust. A high fever is also typically associated with eczema herpeticum, which requires immediate medical attention. 

Occasionally, atopic dermatitis will cause pronounced symptoms in the skin and tissue around the eyes. These symptoms include:

• Inflammation of the insides of eyelids (blepharitis). Redness, irritation and scaly skin may appear on the edges of the eyelids. The scales may be dry or greasy, and eyelashes sometimes drop out. Severe cases of this condition can scar the cornea, damaging vision.
  
  
• Inflammation of the cornea and conjunctiva (atopic keratoconjunctivitis). The conjunctiva is the mucous membrane lining the inner surface of the eyelids and covering the white of the eye. Symptoms are itching, burning, tearing and mucus discharge.
  
  
• Dermatitis of the eyelid. Symptoms include dryness and itching on the inside and outside of the eyelid.
  
  
• Deformity of the cornea (keratoconus). This results from continual rubbing of the eyelid.
  
  
• Cloudy area in the lens of the eye (cataract). Atopic dermatitis may cause cataracts in some patients in their 20s and 30s. The reason for this is unknown.

Individuals diagnosed with atopic dermatitis who receive a smallpox vaccination have a high risk of developing a severe rash known as eczema vaccinatum. The condition can also develop from touching another person’s smallpox vaccination mark before the scab has fallen off. Eczema vaccinatum can cause death in rare cases, though most people afflicted with it do recover.

Some who outgrow childhood atopic dermatitis will develop irritant dermatitis as adults. This is a tendency to develop rashes from exposure to dishwashing detergents, certain chemicals and other potential irritants.

A physician will compile a patient's complete medical history and a list of symptoms before making any diagnosis. A family history of the disorder or of allergic reactions is an important clue. A physician is likely to inspect the appearance and location of the rash, to ask how long the rash has been present and to look for evidence of skin thickening (lichenification).

Patients may also undergo allergy testing to ensure that skin symptoms are not being caused by an allergic reaction rather than atopic dermatitis. This may include blood testing (e.g., RAST) or other forms. However, skin allergy testing may not be accurate in people with skin rash-related problems. Some patients may be placed on an elimination diet to determine if the reaction is being triggered by a particular food.

It is not always possible to diagnose atopic dermatitis on the first visit to a healthcare provider. For example, the physician may request that patients eliminate certain foods from their diet or stop using certain detergents or soaps for a period of time. Patients will then have to return to their provider to see if these steps have been effective in controlling symptoms.

A physician will also rule out other potential causes before diagnosing a case of atopic dermatitis. Sometimes, symptoms that appear to be related to atopic dermatitis actually belong to another skin disorder. Such conditions include:

• Seborrheic dermatitis. Commonly known as "cradle cap," it is similar to atopic dermatitis, but differs in that it is not caused by an allergic response.
  
  
• Psoriasis. This is a rash that is caused by the overproduction of skin cells.
  
  
• Contact dermatitis. Skin condition caused by contact with a substance to which the individual is sensitive or allergic.

Prolonged scratching causes much of the lasting skin damage associated with atopic dermatitis. Therefore, it is crucial to treat the intense itching that often accompanies this disorder.

Medications, ultraviolet light treatments and soaking are the primary methods of treating atopic dermatitis.

• Medications. Various medications are often prescribed to treat symptoms of atopic dermatitis. These medications include:
  
  
  • Antihistamines. These often can effectively relieve minor itchiness. However, they may not be effective for everyone, as the chemical histamine is not always a contributor to atopic dermatitis.
    
    
  • Corticosteroids. Creams and ointments are often prescribed to reduce the itchiness associated with moderate to severe atopic dermatitis. However, they must be used with caution. Powerful corticosteroid creams applied over wide areas of skin can be absorbed into the bloodstream, which can cause medical problems. Only low-dose topical corticosteroids should be used on the face, and great care should be taken not to get the cream into the eyes.
    
    If a corticosteroid treatment begins to lose its effectiveness over time, a physician may suggest a temporary break from the treatment. Petroleum jelly can be applied to keep the skin soft and lubricated. After a week or so, corticosteroid treatment can resume and often will once again be effective.
    
    Rarely, oral corticosteroid treatments may be prescribed for the most stubborn cases of atopic dermatitis. However, these drugs affect the entire body. As a result, they carry a greater risk of side effects. Symptoms often rebound once people stop taking the drugs.
    
    
  • Calcineurin inhibitors. Topical medications that suppress the effects of the body's immune system. They sometimes are prescribed in tandem with corticosteroids and may have fewer side effects than the latter. These drugs cannot be used on children below the age of two.
    
    
  • Antibiotics. These may be prescribed if a case of atopic dermatitis becomes infected.
    
    
  • Skin moisturizers. These help to decrease dryness and itching. 
    
    
• Light therapy. Exposing skin to ultraviolet light has proved to be an effective form of treatment in severe cases of atopic dermatitis. Primarily prescribed by dermatologists, this treatment comes in two forms:
  
  
  • Phototherapy. Uses either ultraviolet A or ultraviolet B light, or a combination of both. This procedure involves a risk of skin cancer or other skin damage.
    
    
  • Photochemotherapy. Uses ultraviolet A light in combination with psoralen medications, which increase skin sensitivity to UV light.  This treatment can be more effective than phototherapy, but the risk of skin cancer or skin damage is also greater.
    
    
• Soaking. While there was at one time a perception that water was bad for skin conditions like atopic dermatitis, many physicians and medical institutions are now embracing the treatment. Water itself is good and hydrates the skin. It is evaporation that dries the skin. After a bath, barriers to evaporation (e.g., Vaseline) should be placed on top of wet areas before toweling off. In fact, many of the more expensive moisturizers are mostly water with a barrier to minimize the damage of evaporation.

Because atopic dermatitis is likely an inherited condition, there is no way to prevent it. However, there are many preventative steps that can be taken to reduce symptoms. These include avoiding the following triggers:

• Excessive heat and sweating
• Emotional stress
• Bacterial skin infections
• Cold air or conditions likely to make the skin dry
• Soaps and detergents
• Fabrics likely to irritate the skin, especially wool
• Tight clothing
• Some skin care products (e.g., astringents, alcohol-containing products)
• Tobacco smoke
• Certain chemicals (e.g., chlorine)
• Acidic foods
• Dust
• Sand

In addition to avoiding triggers, patients can make several behavioral modifications that will help reduce symptoms:

• Avoid taking long or hot baths or showers.
  
  
• After showers and baths, lightly blot skin with towels rather than rubbing intensely.
  
  
• Regular use of unscented moisturizing creams can keep the skin from drying out. Dry skin is more sensitive to irritants, and also lacks a moisture barrier to protect it from irritants.
  
  
• Avoid scratching as much as possible. Excessive scratching can have a devastating long-term effect on skin conditions.
  
  
• Use doctor-approved medications to reduce itching. Because atopic dermatitis almost always causes intense itching, it is important to consult a physician about medications that can safely relieve these symptoms.
  
  
• Keep fingernails short and clean to reduce the chance of infecting the skin when scratching. Cover infants’ hands with mittens or socks to keep them from scratching the area.
  
  
• Learn to manage stress. Patients may benefit from learning stress management techniques and participating in stress-reducing activities such as exercise and meditation. 
  
  
• Use detergents that are perfume and color free. Running clothing through a second rinse cycle can also help remove potentially irritating detergent from clothing.

Studies have shown that children who are breastfed are much less likely to get eczema. In addition, some research indicates that mothers who exclude cow's milk from their diets can significantly reduce their breastfed child's likelihood of developing atopic dermatitis. However, this link has not yet been well-established.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions regarding atopic dermatitis:

1. Do my symptoms suggest atopic dermatitis?
   
   
2. What tests will you use to determine if I have atopic dermatitis?
   
   
3. What treatments are available to me?
   
   
4. Does this condition pose any danger to my overall health?
   
   
5. What are some steps I can take to prevent symptoms?
   
   
6. Will I have this condition for the rest of my life?
   
   
7. Are my children more likely to develop the condition because I have it?
   
   
8. What steps can I take to prevent skin infection?
   
   
9. How will I know if my skin becomes infected?
   
   
10. Can you recommend skin care products, detergents and soaps that won’t irritate my skin?
    
    
11. How can I prevent my child from scratching?