Dermatitis, also known as eczema, is a skin irritation characterized by red, flaky skin, sometimes with cracks or tiny blisters. Dermatitis is extremely itchy, but scratching damages the fragile skin and exacerbates the problem so it is important for people with eczema to try to leave the area alone.
There are several causes of dermatitis, but the most common ones are related to allergies. Atopic eczema , the most common, is caused by general systemic allergic reactions, as opposed to contact with an irritant. It is very common in people with related allergic conditions, including asthma or chronic hay fever. Allergic contact dermatitis, as the name implies, is the result of direct contact with an irritant. One of the most common causes of this form are buttons and rivets in jeans, which contain nickel. Irritant contact dermatitis is similar but is caused by a reaction to some chemical substance, often unrinsed detergents left on clothing or various household chemicals being handled. Often, the inflammation occurs mainly on the hands and feet, as the hands come in contact with most of the chemicals that a person may encounter, and the environment for shoe-clad feet is warm and moist, perfect for fungal infections to begin.
Several other forms appear unrelated to the main allergic causes. Infantile seborrhoeic eczema, also known as cradle cap, forms on the head and quickly spreads. It looks like normal dermatitis, but apparently doesn't itch and eventually goes away on its own. Adult seborrhoeic dermatitis typically affects those between 20 and 40 years old. It affects the scalp, face, and upper body. Varicose eczema occurs later in life, the result of poor circulation in the legs. Finally discoid eczema suddenly appears as small disk shaped spots of severe dermatitis, but disappear on their own.
Stress and anxiety can make otherwise minor outbreaks spread in some people. Deep unresolved or suppressed emotions are believed by some to be expressed externally in the form of physical skin conditions such as dermatitis (this being borne out by increased irritation at times of emotional upset such as anger or stress).
Low humidity is also thought to exacerbate dermatitis.
Dermatitis is often treated by dermatologists with prescribed cortisone (steroid) creams and lotions. While highly effective in some cases, these treatments must be used sparingly; corticosteroids cause the skin to thin and grow fragile with long-term use.
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. As both agents may increase the risk of cancer, both agents now carry "black box" warnings.
Dermatitis severely dries out the skin, and keeping the affected area moistened can promote healing and retain natural moisture. This is the most important self-care treatment that one can use in atopic eczema. The moistening agents are called 'emollients'. The rule to use is: match the thicker ointments to the driest, flakiest skin. Light emollients like Aqueous Cream may dry the skin if it is very flakey, however it is the best form to use at night. Aqueous cream is also the best substitute for soap (and is probably cheaper), soap dries the skin dramatically in eczema and should be completely avoided. Aqueous cream can be used for shaving. Generally twice daily applications of an emollient work best. Emollients should also be added to bath water. Typical emollients in the U.K. are: "Epaderm" - ointment; "Diprobase" - cream; "Doublebase" - cream; Aqueous Cream BNF - cheap light cream.
See also light therapy.
Light therapy using ultraviolet light can help. PUVA, UVB, and Narrow Band UVB are all used. Current research seems to show that Narrow Band UVB is the most effective, plus it has the lowest risk of skin cancer.
Other historical sources - notably traditional Chinese medicine and Western herbalism - suggest a wide variety of treatments, each of which may vary from individual to individual as to efficacy or harm. Toxicity may be present in some.
Some alternative (and even conventional) medicine sources state that oatmeal in solution applied topically has a healing effect. This has been noticed through occupational sources, where a person's skin is often exposed to oatmeal at work, e.g., through baking or milling. Often such people retain exceptionally soft and healthy skin into old age.
More recently, researchers have found signs that the scratching syndrome in some forms of dermatitis is enabled through itching signal transmission in the neural system. Dexamethasone, tacrolimus, naloxone hydrochloride , dibucaine , and capsaicin were each found to suppress the itch cycle in atopic-dermatitis model mice. Other agents that act on nerve transmissions, like menthol, also have been found to mitigate the body's itch signals, providing some relief.
Other than direct treatments of the symptoms, no "cure" for dermatitis is presently known; 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.
Last updated: 08-16-2005 02:53:04