What is eczema?Eczema is a general term for many types of skin inflammation, also known as dermatitis. The most common form of eczema is atopic dermatitis (some people use these two terms 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 people 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. 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.
What are the causes of eczema?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 an 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.
What are the symptoms of eczema?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.
What are the different types of eczema?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.
Contact eczemaContact 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
Seborrheic eczemaSeborrheic 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.
Nummular eczemaNummular eczema (nummular dermatitis) is characterized by coin-shaped patches of irritated
NeurodermatitisNeurodermatitis, 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 dermatitisStasis 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..
Dyshidrotic eczemaDyshidrotic 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.
How is eczema diagnosed?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 diagnosis is not always simple.
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.
What is the treatment for eczema?The goals for the treatment of eczema 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.
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.
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.