Dermatitis

The terms dermatitis and eczema are sometimes used synonymously. However the term eczema is often used to specifically mean atopic dermatitis (also known as atopic eczema). ==Signs and symptoms==

There are several types of dermatitis, including atopic dermatitis, contact dermatitis, stasis dermatitis, and seborrhoeic dermatitis. Symptoms of this type of dermatitis may be very intense and may come and go. Irritant contact dermatitis is usually more painful than itchy. Although the symptoms of atopic dermatitis vary from person to person, the most common symptoms are dry, itchy, red skin on light skin. However, this redness does not appear on darker skin, and dermatitis can appear darker brown or purple in color. Typical affected skin areas include the folds of the arms, the back of the knees, wrists, face and hands. Perioral dermatitis refers to a red, bumpy rash around the mouth. Dermatitis herpetiformis symptoms include itching, stinging, and a burning sensation. Papules and vesicles are commonly present. The small red bumps experienced in this type of dermatitis are usually about 1 cm in size, red in color and may be found symmetrically grouped or distributed on the upper or lower back, buttocks, elbows, knees, neck, shoulders and scalp. The symptoms of seborrhoeic dermatitis, on the other hand, tend to appear gradually, from dry or greasy scaling of the scalp (dandruff) to scaling of facial areas, sometimes with itching, but without hair loss. In newborns, the condition causes a thick and yellowish scalp rash, often accompanied by a diaper rash. In severe cases, symptoms may appear along the hairline, behind the ears, on the eyebrows, on the bridge of the nose, around the nose, on the chest, and on the upper back. File:Eczema.png|Dermatitis File:Eczema-arms.jpg|More severe dermatitis File:Eczema.jpg|A patch of dermatitis that has been scratched File:PLJohnson Complex Eczema.jpg|Complex dermatitis Complications People with eczema should not receive the smallpox vaccination due to risk of developing eczema vaccinatum, a potentially severe and sometimes fatal complication. Other major health risks for people with dermatitis are viral and bacterial infections because atopic dermatitis patients have deficiencies in their proteins and lipids that have barrier functions along with defects in dendritic cells and as a result are unable to keep foreign invaders out, leading to recurring infections. If left untreated, these infections may be life-threatening, so skin barrier improvement (such as daily moisturizing to minimize transepidermal water loss) and anti-inflammatory therapy are recommended as preventative measures. ==Cause==

The cause of dermatitis is unknown, but it is presumed to be a combination of genetic and environmental factors. The hypothesis states that exposure to bacteria and other immune system modulators is important during development, and missing out on this exposure increases the risk for asthma and allergy. Genetic A number of genes have been associated with eczema, one of which affects the production of filaggrin. Eczema occurs about three times more frequently in individuals with celiac disease and about two times more frequently in relatives of those with celiac disease, potentially indicating a genetic link between the conditions. ==Diagnosis==

Diagnosis of eczema is based mostly on the history and physical examination. Those with eczema may be especially prone to misdiagnosis of food allergies. Patch tests are used in the diagnosis of allergic contact dermatitis. Classification The term eczema refers to a set of clinical characteristics. Classification of the underlying diseases has been haphazard with numerous different classification systems, and many synonyms being used to describe the same condition. A type of dermatitis 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 interchangeably for the most common type: atopic dermatitis. Non-allergic eczemas are not affected by this proposal. Histopathologic classification By histopathology, superficial dermatitis (in the epidermis, papillary dermis, and superficial vascular plexus) can basically be classified into either of the following groups: • Vesiculobullous lesions • Pustular dermatosis • Non vesiculobullous, non-pustular :*With epidermal changes :*Without epidermal changes. These characteristically have a superficial perivascular inflammatory infiltrate and can be classified by type of cell infiltrate: Contact Contact dermatitis is of two types: allergic (resulting from a delayed reaction to an allergen, such as poison ivy, nickel, or Balsam of Peru), and irritant (resulting from direct reaction to a detergent, such as sodium lauryl sulfate, for example). Some substances act both as allergens and irritants (wet cement, for example). Other substances cause a problem after sunlight exposure, bringing on phototoxic dermatitis. About three-quarters of cases of contact eczema are of the irritant type, which is the most common occupational skin disease. Contact eczema is curable, provided the offending substance can be avoided and its traces removed from one's environment. (ICD-10 L23; L24; L56.1; L56.0) Seborrhoeic Seborrhoeic dermatitis or seborrheic dermatitis is a condition sometimes classified as a form of eczema that is closely related to dandruff. It causes dry or greasy peeling of the scalp, eyebrows, and face, and sometimes trunk. In newborns, it causes a thick, yellow, crusty scalp rash called cradle cap, which seems related to lack of biotin and is often curable. (ICD-10 L21; L21.0) There is a connection between seborrheic dermatitis and Malassezia fungus, and antifungals such as anti-dandruff shampoo can be helpful in treating it. Neurodermatitis Neurodermatitis (lichen simplex chronicus, localized scratch dermatitis) is an itchy area of thickened, pigmented eczema patch that results from habitual rubbing and scratching. Usually, there is only one spot. Often curable through behaviour modification and anti-inflammatory medication. Prurigo nodularis is a related disorder showing multiple lumps. (ICD-10 L28.0; L28.1) Autoeczematization Autoeczematization (id reaction, auto sensitization) is an eczematous reaction to an infection with parasites, fungi, bacteria, or viruses. It is completely curable with the clearance of the original infection that caused it. The appearance varies depending on the cause. It always occurs some distance away from the original infection. (ICD-10 L30.2) Viral There are eczemas overlaid by viral infections (eczema herpeticum or vaccinatum), and eczemas resulting from underlying disease (e.g., lymphoma). Eczemas originating from ingestion of medications, foods, and chemicals have not yet been clearly systematized. Other rare eczematous disorders exist in addition to those listed here. ==Prevention==

There have been various studies on the prevention of dermatitis through diet, none of which have proven any positive effect. Exclusive breastfeeding of infants during at least the first few months may decrease the risk. There is no good evidence that a mother's diet during pregnancy or breastfeeding affects the risk, There is moderate certainty evidence that the use of skin care interventions such as emollients within the first year of life of an infant's life is not effective in preventing eczema. In fact, it may increase the risk of skin infection and of unwanted effects such as allergic reaction to certain moisturizers and a stinging sensation. There is some evidence that infants with an established egg allergy may have a reduction in symptoms if eggs are eliminated from their diets. • Corn oil: Linoleic acid (LA) • Fish oil: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) • Hemp seed oil: Linoleic acid (LA), and alpha-Linolenic acid (ALA) In the 1950s Arild Hansen showed that infants fed skimmed milk developed essential fatty acid deficiency, which was characterized by increased food intake, poor growth, and scaly dermatitis, and was cured by the administration of corn oil. ==Management==

There is no known cure for some types of dermatitis, with treatment aiming to control symptoms by reducing inflammation and relieving itching. Contact dermatitis is treated by avoiding what is causing it. Seborrheic dermatitis is treated with antifungals such as anti-dandruff shampoo. Lifestyle Bathing once or more a day is recommended, usually for five to ten minutes in warm water. Soaps should be avoided, as they tend to strip the skin of natural oils and lead to excessive dryness. The American Academy of Dermatology suggests using a controlled amount of bleach diluted in a bath to help with atopic dermatitis. People can wear clothing designed to manage the itching, scratching, and peeling. House dust mite reduction and avoidance measures have been studied in low-quality trials and have not shown evidence of improving eczema. Moisturizers Low-quality evidence indicates that moisturizing agents (emollients) may reduce eczema severity and lead to fewer flares. In children, oil–based formulations appear to be better, and water–based formulations are not recommended. Products that contain dyes, perfumes, or peanuts should not be used. a skin disease that can affect people in jobs that regularly come into contact with water, detergents, chemicals or other irritants. Once daily use is generally enough. Red burning skin, where the skin turns red upon stopping steroid use, has been reported among adults who use topical steroids at least daily for more than a year. Antihistamines There is little evidence supporting the use of antihistamine medications for the relief of dermatitis. Sedative antihistamines, such as diphenhydramine, may be useful in those who are unable to sleep due to eczema. Immunosuppressants Topical immunosuppressants like pimecrolimus and tacrolimus may be better in the short term and appear equal to steroids after a year of use. Their use is reasonable in those who do not respond to or are not tolerant of steroids. Treatments are typically recommended for short or fixed periods of time rather than indefinitely. Tacrolimus 0.1% has generally proved more effective than pimecrolimus, and equal in effect to mid-potency topical steroids. There is no association to increased risk of cancer from topical use of pimecrolimus nor tacrolimus. When eczema is severe and does not respond to other forms of treatment, systemic immunosuppressants are sometimes used. Immunosuppressants can cause significant side effects, and some require regular blood tests. The most commonly used are cyclosporin, azathioprine, and methotrexate. Dupilumab is a new medication that improves eczema lesions, especially moderate to severe eczema. Dupilumab, a monoclonal antibody, suppresses inflammation by targeting the interleukin-4 receptor. Antifungals Antifungals are used in the treatment of seborrheic dermatitis. It is a topical Janus kinase inhibitor. which increases 25-hydroxyvitamin D3 in persons in individuals with AD. Light therapy using heliotherapy, balneophototherapy, psoralen plus UVA (PUVA therapy), light has tentative support but the quality of the evidence is not very good compared with narrowband UVB and UVA1. UVB is more effective than UVA1 for treatment of atopical dermatitis. Overexposure to ultraviolet light carries its own risks, particularly that of skin cancer. Alternative medicine Topical Chiropractic spinal manipulation lacks evidence to support its use for dermatitis. There is little evidence supporting the use of psychological treatments. While dilute bleach baths have been used for infected dermatitis, there is no good evidence for the safety or effectiveness of this practice. Supplements • Sulfur: There is currently no scientific evidence for the claim that sulfur treatment relieves eczema. • Chinese herbology: it is unclear whether Chinese herbs help or harm. Dietary supplements are commonly used by people with eczema. • Neither evening primrose oil nor borage seed oil taken orally have been shown to be effective. Both are associated with gastrointestinal upset. ==Prognosis==

Most cases are well managed with topical treatments and ultraviolet light. About 2% of cases are not. In more than 60% of young children, the condition subsides by adolescence. ==Epidemiology==

Globally, dermatitis affected approximately 230 million people as of 2010 (3.5% of the population). Dermatitis is most commonly seen in infancy, with female predominance of eczema presentations occurring during the reproductive period of 15–49 years. In the UK about 20% of children have the condition, while in the United States about 10% are affected. In the developed world there has been rise in the rate of eczema over time. The incidence and lifetime prevalence of eczema in England have been seen to increase in recent times. Dermatitis affected about 10% of U.S. workers in 2010, representing over 15 million workers with dermatitis. Prevalence rates were higher among females than among males and among those with some college education or a college degree compared to those with a high school diploma or less. Workers employed in healthcare and social assistance industries and life, physical, and social science occupations had the highest rates of reported dermatitis. About 6% of dermatitis cases among U.S. workers were attributed to work by a healthcare professional, indicating that the prevalence rate of work-related dermatitis among workers was at least 0.6%. ==Etymology and history==

The term atopic dermatitis was coined in 1933 by Wise and Sulzberger. Sulfur as a topical treatment for eczema was fashionable in the Victorian and Edwardian eras. ==Society and culture==

Some cosmetics are marketed as hypoallergenic to imply that their use is less likely to lead to an allergic reaction than other products. However, the term hypoallergenic is not regulated, and no research has been done showing that products labeled hypoallergenic are less problematic than any others. In 1977, courts overruled the U.S. Food and Drug Administration's regulation of the use of the term hypoallergenic. but this was issued as guidance, not a regulation. ==Research==

Monoclonal antibodies are under preliminary research to determine their potential as treatments for atopic dermatitis, with only dupilumab showing evidence of efficacy, as of 2018. ==Notes==