|Classification and external resources|
Typical, mild dermatitis
Eczema is a disease in a form of dermatitis, or inflammation of the epidermis. 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 lesions. Scratching open a healing lesion may result in scarring. Eczema may be confused with urticaria. In contrast to psoriasis, eczema is often likely to be found on the flexor aspect of joints.
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 and the term for the most common type of eczema (atopic eczema) 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. Non-allergic eczemas are not affected by this proposal.
The classification below is ordered by incidence frequency.
There is no known cure for eczema; therefore, treatments aim to control the symptoms by reducing inflammation and relieving itching.
Dermatitis is often treated with corticosteroids. They do not cure eczema, but are highly effective in controlling or suppressing symptoms in most cases. 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 can be purchased 'over the counter' (e.g., hydrocortisone in UK, United States, Germany, Czech Republic, Australia, Iceland), 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.
Topical immunomodulators like pimecrolimus (Elidel and Douglan) and tacrolimus (Protopic) were developed after corticosteroid treatments, effectively suppressing the immune system in the affected area, and appear to yield better results in some populations. The U.S. Food and Drug Administration has issued a public health advisory about the possible risk of lymph node or skin cancer from use of these products, but many professional medical organizations disagree with the FDA's findings;
When the normal protective barrier of the skin is disrupted (dry and cracked), it allows easy entry for bacteria. Scratching by the patient both introduces infection and spreads it from one area to another. Any skin infection further irritates the skin and a rapid deterioration in the condition may ensue; the appropriate antibiotic should be given.
When eczema is severe and does not respond to other forms of treatment, immunosuppressant drugs are sometimes prescribed. These dampen the immune system and can result in dramatic improvements to the patient's eczema. However, immunosuppressants can cause side effects on the body. As such, patients must undergo regular blood tests and be closely monitored by a doctor. In the UK, the most commonly used immunosuppressants for eczema are ciclosporin(Cyclosporine), azathioprine and methotrexate. These drugs were generally designed for other medical conditions but have been found to be effective against eczema. Commonly prescribed as an immunosuppressant in the United States for Eczema is the steroid Prednisone.
Anti-itch drugs, often antihistamine, may reduce the itch during a flare up of eczema, and the reduced scratching in turn reduces damage and irritation to the skin (the Itch cycle)., however,in eczema, the itch relief is often due to the sedative side effects of these drugs, rather than their specific antihistamine effect. Hence, sedating antihistamines such as promethazine (Phenergan) or diphenhydramine (Benadryl) are more effective at relieving itch than the newer, nonsedating antihistamines. [
Hydrocortisone applied to the skin aids in temporary itch relief.
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, Exederm 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 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, the Mayo Clinic advises against daily baths to avoid skin drying. On the other hand, the American Academy of Dermatology claims "it is a common misconception that bathing dries the skin and should be kept to a bare minimum" and recommends bathing to hydrate skin. They even suggest up to 3 short baths a day for people with severe eczema. According to them, a moisturizer should be applied within 3 minutes to trap the moisture from bath in the skin. U.S. National Eczema Association and the Eczema Society of Canada make similar recommendations. 
Regardless of more or less frequent bathing, the hardness of the bathing water is a major factor. Soft water can have therapeutic effects for people with eczema currently using hard water. An ion exchange water softener can be installed (plumbing required) to reduce the hardness of the water supply. 
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. It may be best to avoid soaps and detergent cleansers all together, except for the armpits, groin and perianal areas, and use cheap bland emolients in the bath or shower, for example aqueous cream.
Dermatological recommendations in choosing a soap generally include:
Instructions for using soap:
While it has been suggested that eczema may sometimes be an allergic reaction to the excrement from house dust mites, with up to 5% of people showing antibodies to the mites, the overall role this plays awaits further corroboration.
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.
Staphylococcus aureus colonies are developed by overly scratching eczema. In a 2009 study from Northwestern University, children with moderate or severe eczema were giving diluted bleach baths and this reduced the severity of the disease. Diluted bleach has been known to have antibacterial qualities. In the study, diluted meant a half cup of bleach to a full tub of water and a bath meant soaking for 5–10 minutes. Antibacterial bath oils containing agents such as triclosan or benzalkonium chloride are available to both moisturise the skin and suppress Staphylococcus aureus. Brand names include Oilatum Plus and QV Flareup Oil.
Light therapy (or Deep penetrating light therapy) using ultraviolet light can help control eczema. UVA is mostly used, but UVB and Narrow Band UVB are also used. Overexposure to ultraviolet light carries its own risks, particularly potential skin cancer from exposure.
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.
Recent studies provide hints that food allergy may trigger atopic dermatitis. For these people, identifying the allergens could lead to an avoidance diet to help minimize symptoms, although this approach is still in an experimental stage. Dietary elements that have been reported to trigger eczema include dairy products, coffee (both caffeinated and decaffeinated), soybean products, eggs, nuts, wheat and maize (sweet corn), though food allergies may vary from person to person. However, in 2009, researchers at National Jewish Medical and Research Center found that eczema patients were especially prone to misdiagnosis of food allergies.
Non-conventional medical approaches include traditional Chinese medicine and Western herbalism. There are a wide variety of treatments, each of which may vary from individual to individual as to efficacy or harm. 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.
In the 1980s, Swedish dermatologist Peter Noren developed a behavioural approach to the treatment of long term atopic eczema. This approach has been further developed by dermatologist Richard Staughton and psychiatrist Christopher Bridgett at the Chelsea and Westminster Hospital in London. 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.
The lifetime clinician-recorded prevalence of eczema has been seen to peak in infancy, with female predominance of eczema presentations occurring during the reproductive period of 15–49 years. Although little data on the trend of eczema prevalence over time exists prior to the Second World War (1939–45), the prevalence of eczema has been found to have increased substantially in the latter half of the 20th Century, with increases in eczema in school-aged children being found to increase between the late 1940’s and 2000. A review of epidemiological data in the UK has also found an inexorable rise in the prevalence of eczema over time. Further recent increases in the incidence and lifetime prevalence of eczema in England have also been reported, such that an estimated 5,773,700 or about one in every nine people have been diagnosed with the disease by a clinician at some point in their lives.
Other than direct treatments of the symptoms, no cure is presently known for most types of dermatitis; even cortisone treatments and immunomodulation may often have only minor effects on what may be a complex problem. As the condition is often related to family history of allergies (and thus heredity), it is probable that gene therapy or genetic engineering might help.
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.
Eczema has increased dramatically in England as a study showed a 42% rise in diagnosis of the condition between 2001 and 2005, by which time it was estimated to affect 5.7 million adults and children. A paper in the Journal of the Royal Society of Medicine says Eczema is thought to be a trigger for other allergic conditions. GP records show over 9 million patients were used by researchers to assess how many people have the skin disorder.
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.
ECZEMA (Gr. K €µa, a cutaneous eruption), one of the most common and important of all skin diseases, consisting of a catarrhal inflammation of the skin originating without visible external irritation, and characterized in some stage of its evolution by a serous exudation. This definition excludes all those forms of inflammation of the skin (dermatitis), which though they may be identical in course and manifestation are yet caused by chemical or mechanical irritants. For an attack of eczema two conditions are necessary: a predisposition or special irritability of the skin, and a directly exciting cause. The first of these conditions is usually inherited or depends on some underlying constitutional state. Thus any organic lesion which may produce oedema and malnutrition of the cutis and epidermis as in kidney diseases, any condition of imperfect metabolism as in dyspepsia or malnutrition, or seborrhoea, may be the predisposing cause. Another influence that has received increasing attention from skin specialists is that of any nervous shock or prolonged mental strain. A "chill" is followed in most people by an ordinary cold, but in some by an attack of eczema. Again, it may be caused by reflex nervous irritation from the uterus, stomach, &c. In some women it always accompanies menstruation, and in others pregnancy. It is of common occurrence in infancy, being attributed by some specialists to dentition, but by others to seborrhoea. Also there is an undoubted relationship between eczema and certain forms of functional neurosis, of which perhaps asthma is the most striking illustration, some physicians considering the latter trouble to be eczema of the bronchial tubes. Sufferers from rheumatism and gout are also specially prone to eczema, though the exact relationship is a much disputed point. There are yet other cases that are undoubtedly microbic, but the micro-organism cannot produce the lesion unless the soil is suitable. As a rule it is not contagious, though when complicated by micro-organisms it may be auto-inoculable, or more rarely inoculable from one patient to another. Except between the ages of ten and twenty years when menstruation is becoming established, and again at the menopause, males are more liable to be attacked than females. In old age the sex influence is lost.
An attack of eczema is usually described as acute or chronic, but the only distinction lies in the greater or less intensity of the inflammation at the time of description: it has nothing to do with the length of time that the disease has lasted. The illness usually begins with a feeling of itching and burning at the site of the lesion. The skin becomes covered with an erythematous blush, on which numerous tiny vesicles form. Swelling, heat, redness and tension are all present. The vesicles grow larger, run together, and either burst or are broken by the patient's scratching, a clear fluid exuding which stiffens linen. The discharge does not dry up at once, but continues to exude - hence the name of "weeping eczema" when this is a prominent symptom. In mild cases the symptoms begin to subside in a few days, the exudation growing less and scales and scabs forming, under which new skin is formed. But where the attack is more acute fresh crops of vesicles spring up and the process repeats itself. In some cases papules are the predominant lesions, but in others, especially when the face is attacked, the erythematous condition is more marked. A severe attack of eczema is usually accompanied by some slight constitutional disturbance, but the general health seldom suffers appreciably, unless, as occasionally, the itching is so bad as to make sleep impossible. The irritation and local heat may be out of all proportion to visible changes in the skin, and in neurotic patients the nervous excitement may be extreme. The attack may centre itself on any part of the body, but there are certain places where it more usually begins, such as the bends of the elbows, the backs of the knees and the groins; the groove behind the ears, the scalp, the palms or the soles, and the breasts of women. According to its position the form of the eczema is somewhat modified. On the front of the legs and arms, from the uniform redness it exhibits in these positions, it is known as eczema rubrum. On the scalp it is generally of the seborrhoeic type, and in children, especially when pediculi are present, it will become pustular from microbic infection. On the palms and soles it brings about a thickening of the epidermis which leads to the formation of cracks, and is hence called eczema rimosum.
The disease can best be treated by a combination of internal and external remedies. Internally, when the inflammation is acute, nothing is so good as antimony, since this relieves the arterial tension and thus reduces the local inflammation. But this must never be given when the patient is suffering from depression. In other cases, especially for babies and children, small doses of calomel are very beneficial; strychnine, phosphorus and ergot are all useful at times. When nervous excitement is marked it must be treated with sedatives. Arsenic and iron are both contraindicated in this disease, since they increase blood formation and hence stimulate the eczematous process. Internal treatment is always best when combined with local treatment, but as a preliminary to this all crusts and scales must first be removed to allow the remedy free access to the disease. Locally the aim is (1) to overcome any source of irritation, (2) to protect the inflamed surface from the air and from microbic infection, and (3) to relieve the itching. The diet should be simple but nourishing, and all hygienic precautions must be taken.