Dermatitis

Eczema
Classification and external resources
Dermatitis of the hand.

Dermatitis (from Greek δέρμα derma "skin" and -ῖτις -itis "inflammation") or eczema (Greek: ἔκζεμα ekzema "eruption") isinflammation of the skin. It is characterized by itchy, erythematous, vesicular, weeping, and crusting patches. The term eczema is also commonly used to describe atopic dermatitis^[1][2] or atopic eczema.^[3]

In some languages, dermatitis and eczema are synonyms, while in other languages dermatitis implies an acute condition and eczema a chronic one.^[4]

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 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.

Treatment is typically with moisturizers and steroid creams.^[3] If these are not effective, creams based on calcineurin inhibitors may be used.^[5] The disease was estimated as of 2010 to affect 230 million people globally (3.5% of the population).^[6]

Classification

More severe eczema

A patch of eczema that has been scratched

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.^[7] Non-allergic eczemas are not affected by this proposal.

Terminology

There are several different types of dermatitis. The different kinds usually have in common an allergic reaction to specific allergens. The term may describe eczema, which is also called dermatitis eczema and eczematous dermatitis. An eczema diagnosis often implies atopic dermatitis (which is very common in children and teenagers) but, without proper context, may refer to any kind of dermatitis.^[8]

In some languages, dermatitis and eczema are synonyms, while in other languages dermatitis implies an acute condition and eczema a chronic one.^[4] The two conditions are often classified together.

Common

• Atopic dermatitis (aka infantile e., flexural e., atopic dermatitis) is an allergic disease believed to have a hereditary component, and often runs in families whose members also have asthma. Itchy rash is particularly noticeable on head and scalp, neck, inside of elbows, behind knees, and buttocks. Experts^[who?] are urging doctors to be more vigilant in weeding out cases that are, in actuality, irritant contact dermatitis. It is very common in developed countries, and rising. (L20)
• Contact dermatitis is of two types: allergic (resulting from a delayed reaction to an allergen, such as poison ivy, nickel, or Balsam of Peru),^[9] and irritant (resulting from direct reaction to a detergent, such as sodium lauryl sulfate, for example).

Some substances act both as allergen and irritant (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. (L23; L24; L56.1; L56.0)

• Xerotic eczema (aka asteatotic e., e. craquele or craquelatum, winter itch, pruritus hiemalis) is dry skin that becomes so serious it turns into eczema. It worsens in dry winter weather, and limbs and trunk are most often affected. The itchy, tender skin resembles a dry, cracked, river bed. This disorder is very common among the older population.Ichthyosis is a related disorder. (L30.8A; L85.0)
• Seborrhoeic dermatitis or Seborrheic dermatitis ("cradle cap" in infants) 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. The condition is harmless except in severe cases of cradle cap. In newborns it causes a thick, yellow, crusty scalp rash called cradle cap, which seems related to lack of biotin and is often curable. (L21; L21.0)

Less common

• Dyshidrosis (aka dyshidrotic e., pompholyx, vesicular palmoplantar dermatitis, housewife's eczema) only occurs on palms, soles, and sides of fingers and toes. Tiny opaque bumps called vesicles, thickening, and cracks are accompanied by itching, which gets worse at night. A common type of hand eczema, it worsens in warm weather. (L30.1)
• Discoid eczema (aka nummular e., exudative e., microbial e.) is characterized by round spots of oozing or dry rash, with clear boundaries, often on lower legs. It is usually worse in winter. Cause is unknown, and the condition tends to come and go. (L30.0)
• Venous eczema (aka gravitational e., stasis dermatitis, varicose e.) occurs in people with impaired circulation, varicose veins, and edema, and is particularly common in the ankle area of people over 50. There is redness, scaling, darkening of the skin, and itching. The disorder predisposes to leg ulcers. (I83.1)
• Dermatitis herpetiformis (aka Duhring's Disease) causes intensely itchy and typically symmetrical rash on arms, thighs, knees, and back. It is directly related to celiac disease, can often be put into remission with appropriate diet, and tends to get worse at night. (L13.0)
• Neurodermatitis (aka 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 behavior modification and anti-inflammatory medication. Prurigo nodularis is a related disorder showing multiple lumps. (L28.0; L28.1)
• Autoeczematization (aka id reaction, autosensitization) 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. (L30.2)
• There are also eczemas overlaid by viral infections (e. herpeticum, e. 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.

Signs and symptoms

Rash symptomatic of dermatitis

Dermatitis symptoms vary with all different forms of the condition. They range from skin rashes to bumpy rashes or including blisters. Although every type of dermatitis has different symptoms, there are certain signs that are common for all of them, including redness of the skin, swelling, itching and skin lesions with sometimes oozing and scarring. Also, the area of the skin on which the symptoms appear tends to be different with every type of dermatitis, whether on the neck, wrist, forearm, thigh or ankle. Although the location may vary, the primary symptom of this condition is itchy skin. More rarely, it may appear on the genital area, such as the vulva or scrotum.^[10] 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. Typical affected skin areas include the folds of the arms, the back of the knees, wrists, face and hands.

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.^[11] Less frequently, the rash may appear inside the mouth or near the hairline.

The symptoms of seborrheic dermatitis on the other hand, tend to appear gradually, from dry or greasy scaling of the scalp (dandruff) tohair loss. In severe cases, pimples 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.^[12] In newborns, the condition causes a thick and yellowish scalp rash, often accompanied by adiaper rash.

Perioral dermatitis refers to a red bumpy rash around the mouth.^[13]

Cause

Complex eczema treated with a combination of antifungal andcorticosteroid creams at the same time.

The cause of eczema is unknown but is presumed to be a combination of genetic and environmental factors.^[14]

Environmental

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.^[15] 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,^[16] with up to 5% of people showing antibodies to the mites,^[17] the overall role this plays awaits further corroboration.^[18]

Genetic

A number of genes have been associated with eczema, one of which is filaggrin.^[3] Genome-wide studies found three new genetic variants associated with eczema: OVOL1, ACTL9 and IL4-KIF3A.^[19]

Eczema occurs about three times more frequently in celiac disease and about two times more frequently in relatives of those with celiac disease, potentially indicating a genetic link between the two conditions.^[20][21]

Diagnosis

Diagnosis of eczema is based mostly on the history and physical examination.^[3] However, in uncertain cases, skin biopsy may be useful.^{[citation needed]} Those with eczema may be especially prone to misdiagnosis of food allergies.^[22]

Patch tests are used in the diagnosis of allergic contact dermatitis.^[23][24]

Prevention

There is no good evidence that a mother's diet during pregnancy, the formula used, or breastfeeding changes the risk.^[25] There is tentative evidence that probiotics in infancy may reduce rates but it is insufficient to recommend its use.^[26]

People with eczema should not get the smallpox vaccination due to risk of developing eczema vaccinatum, a potentially severe and sometimes fatal complication.^[27]

Management

There is no known cure for eczema, with treatment aiming to control symptoms by reducing inflammation and relieving itching.

Lifestyle

Bathing once or more a day is recommended.^[3] It is a misconception that bathing dries the skin in people with eczema.^[28] It is not clear whether dust mite reduction help with eczema.

There has not been adequate evaluation of changing the diet to reduce eczema.^[29][30] There is some evidence that infants with an established egg allergy may have a reduction in symptoms if eggs are eliminated from their diets.^[29] Benefits have not been shown for other elimination diets, though the studies are small and poorly executed.^[29][30]Establishing that there is a food allergy before dietary change could avoid unnecessary lifestyle changes.^[29]

People can also wear clothing designed to manage the itching, scratching and peeling.^[31] Soaps and detergents should not be used on affected skin because they can strip natural skin oils and lead to excessive dryness.

Moisturizers

Moisturizing (also known as emollients) are recommended at least once or twice a day.^[3] Oilier formulations appear to be better and water based formulations are not recommended.^[3] It is unclear if moisturizers that contain ceramides are more or less effective than others.^[32] Products that contain dyes, perfumes, or peanuts should not be used.^[3] Occlusive dressings at night may be useful.^[3]

Medications

There is little evidence for antihistamine and they are thus not generally recommended.^[3] Sedative antihistamines, such as diphenhydramine, may be tried in those who are unable to sleep due to eczema.^[3]

Corticosteroids

If symptoms are well controlled with moisturizers, steroids may only be required when flares occur.^[3] Corticosteroids are effective in controlling and suppressing symptoms in most cases.^[33] Once daily use is generally enough.^[3] For mild-moderate eczema a weak steroid may be used (e.g. hydrocortisone), while in more severe cases a higher-potency steroid (e.g. clobetasol propionate) may be used. In severe cases, oral or injectable corticosteroids may be used. While these usually bring about rapid improvements, they have greater side effects.

Long term use of topical steroids may result in skin atrophy, stria or telangiectasia.^[3] Their use on delicate skin (face or groin) is therefore typically with caution.^[3] They are, however, generally well tolerated.^[34]

Immunosuppressants

Tacrolimus 0.1%

Topical immunosuppressants like pimecrolimus and tacrolimus may be better in the short term and appear equal to steroids after a year of use.^[35] Their use is reasonable in those who do not respond to or are not tolerant of steroids.^[5] Treatments are typically recommended for short or fixed periods of time rather than indefinitely.^[3] Tacrolimus .1% has generally proved more effective than picrolimus, and equal in effect to mid-potency topical steroids.^[25]

The United States Food and Drug Administration has issued a health advisory a possible risk of lymph node or skin cancer from these products,^[36] however subsequent research has not supported these concern.^[5] A major debate, in the UK, has been about the cost of these medications and, given only finite NHS resources, when they are most appropriate to use.^[37]

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 ciclosporin,azathioprine and methotrexate.

Light therapy

Light therapy using ultraviolet light has tentative support but the quality of the evidence is not very good.^[38] A number of different types of light may be used including UVA andUVB.^[39] Overexposure to ultraviolet light carries its own risks, particularly that of skin cancer.^[40]

Alternative medicine

There is currently no scientific evidence for the claim that sulfur treatment relieves eczema.^[41] It is unclear whether Chinese herbs help or harm.^[42] Dietary supplements are commonly used by people with eczema.^[43] Neither evening primrose oil nor borage seed oil taken orally have been shown to be effective.^[44] Both are associated with gastrointestinal upset.^[44] Probiotics do not appear to be effective.^[45] There is insufficient evidence to support the use of zinc, selenium, vitamin D, vitamin E, pyridoxine (vitamin B6), sea buckthorn oil, hempseed oil, sunflower oil, or fish oil as dietary supplements.^[43]

Other remedies lacking evidential support include chiropractic spinal manipulation and acupuncture.^[46] There is little evidence supporting the use of psychological treatments.^[47]While dilute bleach baths have been used for infected dermatitis there is little evidence for this practice.^[48]

Prognosis

Most cases are well managed with topical treatments and ultraviolet light.^[3] About 2% of cases however are not.^[3] In more than 60% the condition goes away by adolescence.^[3]

Epidemiology

Globally eczema affected approximately 230 million people as of 2010 (3.5% of the population).^[49] The lifetime clinician-recorded prevalence of eczema has been seen to peak ininfancy, with female predominance of eczema presentations occurring during the reproductive period of 15–49 years.^[50] In the UK about 20% of children have the condition, while in the United States about 10% are affected.^[3]

Although little data on the rates of eczema over time exists prior to the Second World War (1939–45), the rate of eczema has been found to have increased substantially in the latter half of the 20th Century, with eczema in school-aged children being found to increase between the late 1940s and 2000.^[51] In the developed world there has been rise in the rate of eczema over time.^[3]

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%.^[52]

History

from ancient Greek ἔκζεμα ékzema,^[53]
from ἐκζέ-ειν ekzé-ein,
from ἐκ ek "out" + ζέ-ειν zé-ein "to boil"

(OED)

The term "atopic dermatitis" was coined in 1933 by Wise and Sulzberger.^[54] Sulfur as a topical treatment for eczema was fashionable in the Victorian and Edwardian eras.^[41]

Society and culture

The terms "hypoallergenic" and "doctor tested" are not regulated,^[55] and no research has been done showing that products labeled "hypoallergenic" are in fact less problematic than any others.