Eczema is a general term for many types of skin inflammation (dermatitis). The most common form of eczema is atopic dermatitis (sometimes these two terms are used interchangeably). However, there are many different forms of eczema.
Eczema can affect people of any age, although the condition is most common in infants, and about 85% of those affected have an onset prior to 5 years of age. Eczema will permanently resolve by age 3 in about half of affected infants. In others, the condition tends to recur throughout life. People with eczema often have a family history of the condition or a family history of other allergic conditions, such as asthma or hay fever. The nature of the link between these conditions is inadequately understood. Up to 20% of children and 1%-2% of adults are believed to have eczema. Eczema is slightly more common in girls than in boys. It occurs in people of all races.
Eczema is not contagious, but since it is believed to be at least partially inherited, it is not uncommon to find members of the same family affected.
Doctors do not know the exact cause of eczema, but a defect of the skin that impairs its function as a barrier, possibly combined with an abnormal function of the immune system, are believed to be important factors. Studies have shown that in people with atopic dermatitis there are gene defects that lead to abnormalities in certain proteins (such as filaggrin) that are important in maintaining the barrier of normal skin.
Some forms of eczema can be triggered by substances that come in contact with the skin, such as soaps, cosmetics, clothing, detergents, jewelry, or sweat. Environmental allergens (substances that cause allergic reactions) may also cause outbreaks of eczema. Changes in temperature or humidity, or even psychological stress, can lead to outbreaks of eczema in some people.
Eczema most commonly causes dry, reddened skin that itches or burns, although the appearance of eczema varies from person to person and varies according to the specific type of eczema. Intense itching is generally the first symptom in most people with eczema. Sometimes, eczema may lead to blisters and oozing lesions, but eczema can also result in dry and scaly skin. Repeated scratching may lead to thickened, crusty skin.
While any region of the body may be affected by eczema, in children and adults, eczema typically occurs on the face, neck, and the insides of the elbows, knees, and ankles. In infants, eczema typically occurs on the forehead, cheeks, forearms, legs, scalp, and neck.
Eczema can sometimes occur as a brief reaction that only leads to symptoms for a few hours or days, but in other cases, the symptoms persist over a longer time and are referred to as chronic dermatitis.
Atopic dermatitis is the most common of the many types of eczema, and sometimes people use the two terms interchangeably. But there are many terms used to describe specific forms of eczema that may have very similar symptoms to atopic dermatitis. These are listed and briefly described below.
Atopic dermatitis is a chronic skin disease characterized by itchy, inflamed skin and is the most common cause of eczema. The condition tends to come and go, depending upon exposures to triggers or causative factors. Factors that may cause atopic dermatitis (allergens) include environmental factors like molds, pollen, or pollutants; contact irritants like soaps, detergents, nickel (in jewelry), or perfumes; food allergies; or other allergies. Around two-thirds of those who develop the condition do so prior to 1 year of age. When the disease starts in infancy, it is sometimes termed infantile eczema. Atopic dermatitis tends to run in families, and people who develop the condition often have a family history of other allergic conditions such as asthma or hay fever.
Contact eczema (contact dermatitis) is a localized reaction that includes redness, itching, and burning in areas where the skin has come into contact with an allergen (an allergy-causing substance to which an individual is sensitized) or with a general irritant such as an acid, a cleaning agent, or other chemical. Other examples of contact eczema include reactions to laundry detergents, soaps, nickel (present in jewelry), cosmetics, fabrics, clothing, and perfume. Due to the vast number of substances with which individuals have contact, it can be difficult to determine the trigger for contact dermatitis. The condition is sometimes referred to as allergic contact eczema (allergic contact dermatitis) if the trigger is an allergen and irritant contact eczema (irritant contact dermatitis) if the trigger is an irritant. Skin reactions to poison ivy and poison sumac are examples of allergic contact eczema. People who have a history of allergies have an increased risk for developing contact eczema.
Seborrheic eczema (seborrheic dermatitis) is a form of skin inflammation of unknown cause. The signs and symptoms of seborrheic eczema include yellowish, oily, scaly patches of skin on the scalp, face, and occasionally other parts of the body. Dandruff and "cradle cap" in infants are examples of seborrheic eczema. It is commonplace for seborrheic dermatitis to inflame the face at the creases of the cheeks and/or the nasal folds. Seborrheic dermatitis is not necessarily associated with itching. This condition tends to run in families. Emotional stress, oily skin, infrequent shampooing, and weather conditions may all increase a person's risk of developing seborrheic eczema. One type of seborrheic eczema is also common in people with AIDS.
Nummular eczema (nummular dermatitis) is characterized by coin-shaped patches of irritated skin -- most commonly located on the arms, back, buttocks, and lower legs -- that may be crusted, scaling, and extremely itchy. This form of eczema is relatively uncommon and occurs most frequently in elderly men. Nummular eczema is usually a chronic condition. A personal or family history of atopic dermatitis, asthma, or allergies increases the risk of developing the condition.
Neurodermatitis, also known as lichen simplex chronicus, is a chronic skin inflammation caused by a scratch-itch cycle that begins with a localized itch (such as an insect bite) that becomes intensely irritated when scratched. Women are more commonly affected by neurodermatitis than men, and the condition is most frequent in people 20-50 years of age. This form of eczema results in scaly patches of skin on the head, lower legs, wrists, or forearms. Over time, the skin can become thickened and leathery. Stress can exacerbate the symptoms of neurodermatitis.
Stasis dermatitis is a skin irritation on the lower legs, generally related to the circulatory problem known as venous insufficiency, in which the function of the valves within the veins has been compromised. Stasis dermatitis occurs almost exclusively in middle-aged and elderly people, with approximately 6%-7% of the population over 50 years of age being affected by the condition. The risk of developing stasis dermatitis increases with advancing age. Symptoms include itching and/or reddish-brown discoloration of the skin on one or both legs. Progression of the condition can lead to the blistering, oozing skin lesions seen with other forms of eczema, and ulcers may develop in affected areas. The chronic circulatory problems lead to an increase in fluid buildup (edema) in the legs. Stasis dermatitis has also been referred to as varicose eczema.
Dyshidrotic eczema (dyshidrotic dermatitis) is an irritation of the skin on the palms of hands and soles of the feet characterized by clear, deep blisters that itch and burn. The cause of dyshidrotic eczema is unknown. Dyshidrotic eczema is also known as vesicular palmoplantar dermatitis, dyshidrosis, or pompholyx. This form of eczema occurs in up to 20% of people with hand eczema and is more common during the spring and summer months and in warmer climates. Males and females are equally affected, and the condition can occur in people of any age.
To diagnose eczema, doctors rely on a thorough physical examination of the skin as well as the patient's account of the history of the condition. In particular, the doctor will ask when the condition appeared, if the condition is associated with any changes in environment or contact with certain materials, and whether it is aggravated in any specific situations. Eczema may have a similar appearance to other diseases of the skin, including infections or reactions to certain medications, so the Eczema diagnosis is not always simple. In some cases, a biopsy of the skin may be taken in order to rule out other skin diseases that may be producing signs and symptoms similar to eczema.
If a doctor suspects that a patient has allergic contact dermatitis, allergy tests, possibly including a skin "patch test," may be carried out in an attempt to identify the specific trigger of the condition.
There are no laboratory or blood tests that can be used to establish the diagnosis of eczema.
The goals for Eczema treatments
are to prevent itching, inflammation, and worsening of the condition. Treatment of eczema may involve both lifestyle changes and the use of medications. Treatment is always based upon an individual's age, overall health status, and the type and severity of the condition.
Keeping the skin well hydrated through the application of creams or ointments (with a low water and high oil content) as well as avoiding over-bathing is an important step in treatment. It is recommended to apply emollient creams such as petrolatum-based creams to the body immediately after a five-minute lukewarm bath in order to seal in moisture while the body is still wet. Lifestyle modifications to avoid triggers for the condition are also recommended.
Corticosteroid creams are sometimes prescribed to decrease the inflammatory reaction in the skin. These may be mild-, medium-, or high-potency corticosteroid creams depending upon the severity of the symptoms. If itching is severe, oral antihistamines may be prescribed. To control itching, the sedative type antihistamine drugs (for example, diphenhydramine [Benadryl], hydroxyzine [Atarax, Vistaril], and cyproheptadine) appear to be most effective.
In some cases, a short course of oral corticosteroids (such as prednisone) is prescribed to control an acute outbreak of eczema, although their long-term use is discouraged in the treatment of this non life-threatening condition because of unpleasant and potentially harmful side effects. The oral immunosuppressant drug cyclosporine has also been used to treat some cases of eczema. Ultraviolet light therapy (phototherapy) is another treatment option for some people with eczema.
Finally, two topical (cream) medications have been approved by the U.S. FDA for the treatment of eczema: tacrolimus (Protopic) and pimecrolimus (Elidel). These drugs belong to a class of immune suppressant drugs known as calcineurin inhibitors and are indicated only in patients over 2 years of age. In January 2006, the FDA issued a black box warning stating the long-term safety of calcineurin inhibitors has not been established. Although a causal relationship has not been established, rare cases of malignancy have been reported with their use. It is recommended that these drugs only be used as second-line therapy for cases that are unresponsive to other forms of treatment and that their use be limited to the minimum time periods needed to control symptoms. Use of these drugs should also be limited in people who have compromised immune systems.
Eczema and Food Allergies
NEW YORK – Children with atopic dermatitis have a high risk of food allergies – although these allergies are not always easy to pinpoint.
"In this population, up to 20% of [those] with mild to moderate atopic dermatitis and 30%-40% of the severe patients will have a true food allergy," that can be confirmed with an open food challenge. Dr. Lawrence F. Eichenfield said at the American Academy of Dermatology’s 2010 meeting.
However, he said, positive skin prick testing – a common form of allergen identification – isn’t a very accurate way to detect the allergies. As a result, parents of children with atopic dermatitis (AD) will frequently state that their child has a food allergy, when, in fact, none exists.
A new national guideline helps clarify that issue, he said. Published in late 2010, "Guidelines for the Diagnosis and Management of Food Allergy in the United States," from the National Institute of Allergy and Infectious Diseases, provides some helpful information for dermatologists trying to make the AD/food allergy connection.
The document defines a food allergy as an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food. Skin prick testing, however, can only identify sensitization to a food, which doesn’t necessarily correlate with a clinical event, said Dr. Eichenfield, a professor of clinical pediatrics and dermatology at the University of California, San Diego.
"It’s very clearly written in the guidelines that an individual can develop allergic sensitization without having clinical symptoms on exposure to the food. Therefore, skin testing is not sufficient to say there is a food allergy."
Nevertheless, a common clinical scenario in the pediatric dermatology office is a parent who claims the child is allergic to a given food – most often eggs, soy, milk, wheat, or peanuts – because of a positive skin test. "What people don’t understand is, these tests are neither very sensitive nor specific," he said.
The specificity of skin prick testing hovers at about 85%, while the sensitivity is around 75%. "That means if we assume a 5% true milk allergy in a group of 1,000 people, skin prick testing will identify 42 of the 50 with a true allergy, miss 8 of those with the allergy, and give a false positive result to 238 people without the allergy," he said. "It’s a problem when you start labeling someone as having an allergy with just a positive test, but no clinical indicator."
The national guidelines stress that both family history and AD are risk factors for food allergy. The report suggests that children younger than 5 years who have moderate to severe AD that is uncontrolled despite optimal treatment, should be tested for allergies to milk, egg, peanut, soy and wheat. A positive, reliable history of a clinical reaction immediately after exposure to a specific food is also grounds for an investigation, according to the report.
Oral food challenge is probably the best way to determine a true food allergy, but can only be carried out in an environment set up to cope with severe reactions – usually an allergist’ s office. The good news is that the common overrepresentation of "food allergies" among children with AD means that many can safely consume foods that have been, literally, taken off the table.
A 2010 retrospective study looked at 125 children with atopic dermatitis, 44 of whom had suspected allergies to a variety of foods. All of them underwent oral food challenges. At baseline, there were 111 reports of food avoidance due to positive skin prick testing – foods included egg, fruit, meat, vegetables, milk, soy, wheat, shellfish, oats, and peanuts (J. Pediatr. 2010;158:578-83).
"Except for wheat, 80% or more of the oral food challenges were negative to the foods being avoided," wrote Dr. David M. Fleisher of the University of Colorado, Denver, and colleagues. This study was funded by National Jewish Health and the authors declared no conflicts. The only positive reactions were for egg, banana, peanut, soy, and wheat.
"Depending on the reason for avoidance, 84%-93% of the foods being avoided were successfully reintroduced into the diet," Dr. Eichenfield said.
The new management guidelines have affected the way he assesses AD patients, Dr. Eichenfield added. "Now I ask about food allergy reactions. If I find anything positive, I take a very detailed history, including the type of reaction, the time course, and the consistency of it after exposure to the food. Many times, just by asking, you will uncover a very significant reaction, like contact dermatitis, urticaria, or even anaphylaxis."
The guidelines note that anaphylaxis can be a real - and life-threatening – complication of food allergy. Parents of children with a proven food allergy should be experts in avoiding the food and in emergency management. "The standard management is to write a prescription for an Epi-Pen and make sure they know how to use it," Dr. Eichenfield said.
He’s also more likely to refer children with moderate to severe AD and persistent flares for testing now. "I am more liberal about using the allergist to evaluate these patients, with the understanding that a positive test may not change the eczema, but with the hope that if there is an avenue that might help, it’s one we want to explore."
Dr. Eichenfield had no financial disclosures.
Psoriasis and eczema
By Maureen Salamon
WEDNESDAY, July 20 (HealthDay News) -- Psoriasis and eczema both cause red, scaly skin rashes, but the similarities between the two common, distressing conditions typically end there.
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And now, examining patients suffering from both ailments (a very rare phenomenon), German scientists have teased out the opposing immune system responses that prompt skin flare-ups for both diseases.
They believe the findings could one day lead to more targeted, effective treatments.
The study, published in the July 21 issue of the New England Journal of Medicine, evaluated three patients with both psoriasis and eczema and noted that the T-cells -- types of white blood cells that fight infection -- found in psoriasis lesions differed from those found in eczema lesions.
The findings suggest that these T-cells migrate to the skin in response to distinct environmental triggers, not that the skin cells themselves are abnormal in either inflammatory condition, the study authors said.
"It's just another way for doctors to understand immune pathways and where they go awry," explained Dr. Doris Day, a dermatologist at Lenox Hill Hospital in New York City, who was not involved in the study. "It puts our understanding exponentially ahead and confuses us at the same time, because it's not supposed to happen [that patients can have both conditions]. The study definitely has value, and they're not making any claims or recommendations."
The most prevalent autoimmune disease in the United States, psoriasis affects up to 7.5 million Americans and is thought to arise from a combination of genetic and environmental triggers, according to the National Psoriasis Foundation. Eczema, on the other hand, is thought to be an allergic response and often occurs simultaneously in those with asthma or food allergies, according to the American Academy of Allergy, Asthma and Immunology. It is often outgrown by adulthood.
Psoriasis lesions in the study participants contained large numbers of so-called Th1 and Th17 cells, whereas eczema lesions had higher amounts of Th2 and Th22 cells. The researchers expanded their testing to include five patients with psoriasis and skin allergies to nickel -- a much more common combination that prompts an eczema-like reaction -- to confirm a similar T-cell response to psoriasis.
The study also found that all eczema lesions, but none in psoriasis, harbored Staphylococcus aureus bacteria, confirming that T-cells in psoriasis appear to prompt an innate immune response that's different from what is seen in eczema.
Dr. Jerry Bagel, a spokesman for the National Psoriasis Foundation and associate clinical professor of dermatology at Columbia University in New York City, said the research indicates that eczema and psoriasis "are clearly distinct entities, but there is some crossover immunologically."
If scientists could determine which antigens stimulate each condition -- a job that would likely take years -- they might find new ways to stop the disorders from developing in predisposed people, Bagel and Day agreed.
Current psoriasis treatments, which include both topical and systemic drugs, aim to suppress the body's immune response and slow down the skin cell growth cycle that leads to its trademark red, scaly plaques. Eczema treatments can involve both medications and lifestyle changes that cut itching, inflammation and worsening of the condition.
But, perhaps in the future, "they could have more direct testing to see if patients have an immune system alteration," Day said. "The more we understand the pathways and how the immune system responds to insults from the external world . . . we can adjust steps along the way, or medications that minimize side effects and maximize safety."
Help Prevent Eczema Flares
(HealthDay News) -- Eczema is a chronic condition that makes the skin red, dry and itchy.
The American Academy of Family Physicians suggests how to prevent flares of eczema:
Stay away from irritants such as harsh soaps, detergents, gasoline and cleaning solutions.
Wear clothing made of cotton, and avoid wool and synthetic fabrics that can irritate the skin.
Take short, lukewarm baths or showers and wash with a mild cleanser. Avoid hot water.
Pat skin dry after a bath or shower and immediately apply moisturizer.
Make sure you moisturize your skin every day. Avoid scratching your skin.
Avoid getting very sweaty or overheating.
Find ways to control stress.