Inflammation of the skin, usually itchy, with redness, swelling, and blistering. Causes and patterns vary. Contact dermatitis appears at the site of contact with an irritating substance or allergen. Atopic dermatitis, with patches of dry skin, occurs in infants, children, and young adults with genetic hypersensitivities (atopy). Stasis dermatitis affects the ankles and lower legs because of chronic poor blood flow in the veins. Seborrheic dermatitis appears as scaly skin, most often on the scalp (dandruff) and areas rich in sebaceous glands. Neurodermatitis is apparently caused by repeated scratching of an itchy skin area.
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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. Non-allergic eczemas are not affected by this proposal.
The classification below is ordered by incidence frequency.
Given the many possible reasons for eczema flare-ups, a doctor is likely to ascertain a number of other things before making a judgment:
To determine whether an eczema flare is the result of an allergen, a doctor may test the blood for the levels of antibodies and the numbers of certain types of cells. In eczema, the blood may show a raised IgE or an eosinophilia.
The blood can also be sent for a specific test called Radioallergosorbent Test (RAST) or a Paper Radioimmunosorbent Test (PRIST). In the test, blood is mixed separately with many different allergens and the antibody levels measured. High levels of antibodies in the blood signify an allergy to that substance. Allergic diseases are a rapidly growing health problem. A precise, reliable in vitro test for IgE antibodies to specific substances is a valuable tool to support the clinician in making diagnoses of or excluding allergy, prescribing and following up treatment, and predicting disease development.
In order to understand an evolving allergic disease it is necessary to gain more detailed information about the ongoing IgE sensitization process in the patient. Such accurate information can only be obtained through quantitative measurements of the levels of IgE antibodies to different allergens in the blood. One such quantitative test is the ImmunoCAP test giving the results in kU A /l rather than in classes, the requirements for accuracy are even higher.
Another test for eczema is Patch test. The suspected irritant is applied to the skin and held in place with an adhesive patch. Another patch with nothing is also applied as a control. After 24 to 48 hours, the patch is removed. If the skin under the suspect patch is red and swollen, the patch test result is considered positive and suggests that the person is probably allergic to the suspected irritant.
Blood tests and biopsies are not always necessary for eczema diagnosis.
There is no known cure for eczema, thus treatments aim to control the symptoms: reduce inflammation and relieve itching.
For mild-moderate eczema a weak steroid may be used (e.g. hydrocortisone or desonide), whilst more severe cases require a higher-potency steroid (e.g. clobetasol propionate, fluocinonide). Medium-potency corticosteroids such as clobetasone butyrate (Eumovate), Betamethasone Valerate (Betnovate) or triamcinolone are also available. Generally medical practitioners will prescribe the less potent ones first before trying the more potent ones. In many countries, weak steroids such as hydrocortisone can be purchased 'over the counter' (e.g., hydrocortisone in UK, US, Germany, Czechia), while the more potent ones require a prescription.
Prolonged use of topical corticosteroids is thought to increase the risk of possible side effects, the most common of which is the skin becoming thin and fragile (atrophy). Because of this, if used on the face or other delicate skin, only a low-strength steroid should be used. Additionally, high-strength steroids used over large areas, or under occlusion, may be significantly absorbed into the body, causing hypothalamic-pituitary-adrenal axis suppression (HPA axis suppression). Finally by their immunosuppressive action they can, if used without antibiotics or antifungal drugs, lead to some skin infections (fungal or bacterial). Care must be taken to avoid the eyes, as topical corticosteroids applied to the eye can cause glaucoma or cataracts.
Because of the risks associated with this type of drug, a steroid of an appropriate strength should be sparingly applied only to control an episode of eczema. Once the desired response has been achieved, it should be discontinued and replaced with emollients as maintenance therapy. Corticosteroids are generally considered safe to use in the short- to medium-term for controlling eczema, with no significant side effects differing from treatment with non-steroidal ointment.
However, recent research has shown that topically applied corticosteroids did not significantly increase the risk of skin thinning, stretch marks or HPA axis suppression (and where such suppression did occur, it was mild and reversible where the corticosteroids were used for limited periods of time). Further, skin conditions are often under-treated because of fears of side effects. This has led some researchers to suggest that the usual dosage instructions should be changed from "Use sparingly" to "Apply enough to cover affected areas," and that specific dosage directions using "fingertip units" or FTU's be provided, along with photos to illustrate FTU's.
In severe cases, oral cortisosteroids such as prednisolone or injections such as triamcinolone injections may also be prescribed. While these usually bring about rapid improvements, they should not be taken for any length of time and the eczema often returns to its previous level of severity once the medication is stopped. In the case of triamcinolone injections, a waiting period between treatments may be required.
Capsaicin applied to the skin acts as a counter irritant (see Gate control theory of nerve signal transmission). Other agents that act on nerve transmissions, like menthol, also have been found to mitigate the body's itch signals, providing some relief. Recent research suggests Naloxone hydrochloride and dibucaine suppress the itch cycle in atopic-dermatitis model mice as well.
Eczema can be exacerbated by dryness of the skin. Moisturizing is one of the most important self-care treatments for sufferers of eczema. Keeping the affected area moistened can promote skin healing and relief of symptoms.
Soaps and harsh detergents should not be used on affected skin because they can strip natural skin oils and lead to excessive dryness. Instead, the use of moisturizing body wash, or an emollient like aqueous cream, will maintain natural skin oils and may reduce some of the need to moisturize the skin. Another option is to try bathing using colloidal oatmeal bath treatments. In addition to avoiding soap, other products that may dry the skin such as powders or perfume should also be avoided.
Moistening agents are called 'emollients'. In general, it is best to match thicker ointments to the driest, flakiest skin. Light emollients like aqueous cream may not have any effect on severely dry skin. Some common emollients for the relief of eczema include Oilatum, Balneum, Medi Oil, Diprobase, bath oils and aqueous cream. Sebexol, Epaderm ointment and Eucerin lotion or cream may also be helpful with itching. Lotions or creams may be applied directly to the skin after bathing to lock in moisture. Moisturizing gloves (gloves which keep emollients in contact with skin on the hands) can be worn while sleeping. Generally, twice-daily applications of emollients work best. While creams are easy to apply, they are quickly absorbed into the skin, and therefore need frequent reapplication. Ointments, with less water content, stay on the skin for longer and need fewer applications, but they can be greasy and inconvenient. Steroids such as Betnovate may also be mixed in with ointments.
For unbroken skin, direct application of waterproof tape with or without an emollient or prescription ointment can improve moisture levels and skin integrity which allows the skin to heal. This treatment regimen can also help prevent the skin from cracking, as well as put a stop to the itch cycle. The end result is reduced lichenification (the roughening of skin from repeated scratching). Taping works best on skin away from joints.
There is a disagreement whether baths are desirable or a necessary evil. For example Mayo Clinic advises against daily baths to avoid skin drying.. On the other hand, U.S. National Eczema Association claims that "the best way to get water into your skin is to briefly soak in a bath or shower and to moisturize immediately afterwards.. Similarly, The Eczema Society of Canada recommends frequent baths and American Academy of Dermatology claims that bathing can hydrate skin.
Recently, ceramides, which are the major lipid constituent of the stratum corneum, have been used in the treatment of eczema. They are often one of the ingredients of modern moisturizers. These lipids were also successfully produced synthetically in the laboratory.
However, detergents are so ubiquitous in modern environments in items like tissues, and so persistent on surfaces, "safe" soaps are necessary to remove them from the skin in order to control eczema. Although most eczema recommendations use the terms "detergents" and "soaps" interchangeably, and tell eczema sufferers to avoid both, detergents and soaps are not the same and are not equally problematic to eczema sufferers. Detergents, often made from petrochemicals, increase the permeability of skin membranes in a way that soaps and water alone do not. Sodium lauryl sulfate, the most common household detergent, has been shown to amplify the allergenicity of other substances ("increase antigen penetration").
Unfortunately there is no one agreed-upon best kind of skin cleanser for eczema sufferers. Different clinical tests, sponsored by different personal product companies, unsurprisingly tout various brands as the most skin-friendly based on specific properties of various products and different underlying assumptions as to what really determines skin friendliness. The terms "hypoallergenic" and "doctor tested" are not regulated, and no research has been done showing that products labeled "hypoallergenic" are in fact less problematic than any others.
Dermatological recommendations in choosing a soap generally include:
Instructions for using soap:
Various measures may reduce the amount of mite antigens, in particular swapping carpets for hard surfaces. Effectiveness of vacuum cleaners is dependent upon the characteristics of the carpet pile, but in other studies daily vacuuming did not affect levels of mites. However it is not clear whether such measures actually help patients with eczema. A controlled study suggested that a number of environmental factors such as air exchange rates, relative humidity and room temperature (but not the level of house dust mites) might have an effect on the condition.
When light therapy alone is found to be ineffective, the treatment is performed with the application (or ingestion) of a substance called psoralen. This PUVA (Psoralen + UVA) combination therapy is termed photo-chemotherapy. Psoralens make the skin more sensitive to UV light, thus allowing lower doses of UVA to be used. However, the increased sensitivity to UV light also puts the patient at greater risk for skin cancer.
It has been suggested that eczema can be cured by UV Rays, i.e. sunbathing or using tanning beds. Some people have been able to abate their symptoms through this treatment, but this should be supervised by a dermatologist.
Dietary elements that have been reported to trigger eczema include dairy products and coffee (both caffeinated and decaffeinated), soybean products, eggs, nuts, wheat and maize (sweet corn), though food allergies may vary from person to person.
Recently German scientists discovered that a diet rich in Omega-3 may be able to reduce symptoms.
Non-conventional medical approaches include traditional Chinese medicine and Western herbalism. There is wide variety of treatments, each of which may vary from individual to individual as to efficacy or harm. For example, according to American Academy of Dermatology, while certain blends of Chinese herbal medicines have been proven effective in controlling eczema, they have also have proven toxic with severe consequences. Patients should inform their doctor/allergist/dermatologist if they are pursuing one of these treatment routes.
Alleged remedies include:
Patients can also wear clothing designed specifically to manage the itching, scratching and peeling associated with eczema.
Patients undergo a 6 week monitored program involving scratch habit reversal and self awareness of scratching levels. For long term eczema sufferers, scratching can become habitual. Sometimes scratching becomes a reflex, resulting in scratching without conscious awareness, rather than from the feeling of itchiness itself. The habit reversal program is done in conjunction with the standard applied emollient/corticosteroid treatments so that the skin can heal. It also reduces future scratching, as well as reduces the likelihood of further flareups. The behavioural approach can give an eczema sufferer some control over the degree of severity of eczema.
Damage from the enzymatic activity of allergens is usually prevented by the body's own protease inhibitors, such as, LEKTI, produced from the gene SPINK5. Mutations in this gene are known to cause Netherton’s syndrome, which is a congenital erythroderma. These patients nearly always develop atopic disease, including hay fever, food allergy, urticaria and asthma. Such evidence supports the hypothesis that skin damage from allergens may be the cause of eczema, and may provide a venue for further treatment.
Another study identified a gene that the researchers believe to be the cause of inherited eczema and some related disorders. The gene produces the protein filaggrin, the lack of which causes dry skin and impaired skin barrier function.
A recent study indicated that two specific chemicals found in the blood are connected to the itching sensations associated with eczema. The chemicals are Brain-derived neurotrophic factor (BDNF) and Substance P.
In June, 2007, Science magazine reported that an American soldier who had been vaccinated for smallpox, a vaccine that contains live vaccinia virus, had transmitted vaccinia virus to his two-year-old son. The soldier and his son both had a history of eczema. The son rapidly came down with a rare side effect, eczema vaccinatum, which had been seen during the 1960s when children were routinely vaccinated against smallpox. The child developed a severe full-body pustular rash, his abdomen filled with fluid, and his kidneys nearly failed. Intense consultation with experts from the Centers for Disease Control and Prevention and a donation of an experimental antiviral drug by SIGA Technologies saved the child's life. Those with a family history of eczema are advised not to accept the smallpox vaccination, or anything else that contains live vaccinia virus.