Eczema – Wikipedia, the free encyclopedia

Eczema (from Greek: kzema, "to boil over") also known as atopic dermatitis[1] is a form of chronic inflammation of the skin.[2]

The term eczema is broadly applied to a range of persistent skin conditions. These include dryness and recurring skin rashes that are characterized by one or more of these symptoms: redness, skin edema (swelling), itching and dryness, crusting, flaking, blistering, cracking, oozing, or bleeding. Areas of temporary skin discoloration may appear and are sometimes due to healed injuries. Scratching open a healing lesion may result in scarring and may enlarge the rash.

The word eczema comes from Greek, meaning "to boil over". Dermatitis comes from the Greek word for skin and both terms refer to the same skin condition. In some languages, dermatitis and eczema are synonymous, while in other languages dermatitis implies an acute condition and "eczema" a chronic one.[3] The two conditions are often classified together.

The term eczema refers to a set of clinical characteristics. Classification of the underlying diseases has been haphazard and unsystematic, with many synonyms used to describe the same condition. A type of eczema may be described by location (e.g., hand eczema), by specific appearance (eczema craquele or discoid), or by possible cause (varicose eczema). Further adding to the confusion, many sources use the term eczema for the most common type of eczema (atopic dermatitis) interchangeably.

The European Academy of Allergology and Clinical Immunology (EAACI) published a position paper in 2001 which simplifies the nomenclature of allergy-related diseases including atopic and allergic contact eczemas.[4] Non-allergic eczemas are not affected by this proposal.

The cause of eczema is unknown but is presumed to be a combination of genetic and environmental factors.[5]

The hygiene hypothesis postulates that the cause of asthma, eczema, and other allergic diseases is an unusually clean environment. It is supported by epidemiologic studies for asthma.[6] The hypothesis states that exposure to bacteria and other immune system modulators is important during development, and missing out on this exposure increases risk for asthma and allergy.

While it has been suggested that eczema may sometimes be an allergic reaction to the excrement from house dust mites,[7] with up to 5% of people showing antibodies to the mites,[8] the overall role this plays awaits further corroboration.[9]

Researchers have compared the prevalence of eczema in people who also suffer from celiac disease to eczema prevalence in control subjects, and have found that eczema occurs about three times more frequently in celiac disease patients and about two times more frequently in relatives of celiac patients, potentially indicating a genetic link between the two conditions.[10][11]

The failure of the body to metabolize linoleic acid into y-linoleic acid (GLA) was thought to be a possible cause of eczema, however the largest and best reported studies into the efficacy of GLA supplements in the treatment of eczema failed to show any benefit.[12]

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Eczema - Wikipedia, the free encyclopedia