What is atopic dermatitis? What is eczema?

Atopic dermatitis and eczema both refer to skin conditions. Atopic dermatitis is a cause of eczema, which refers to skin conditions that cause inflammation and irritation. The terms are sometimes used interchangeably.

Atopic dermatitis is a common chronic skin condition that results in red, inflamed, dry, and itchy skin. Other symptoms of atopic dermatitis include blisters (vesicles), skin cracking, crusting, weeping, and scaling. Atopic dermatitis can affect adults, but it is most commonly seen in babies and young children. Triggers that may cause or worsen atopic dermatitis include low humidity, cold weather, seasonal allergies, and exposure to harsh soaps and detergents. Atopic dermatitis treatment involves use of moisturizers such as petroleum jelly and topical steroids to reduce inflammation and itching.

Eczema is not a condition in itself, but a description for a group of skin diseases that cause skin inflammation and irritation. Eczema itself is not contagious; however, if the blisters become infected, that infection may spread. Atopic dermatitis is the most common type of eczema. Symptoms of eczema include itching along with blisters that ooze and eventually produce crusted, thickened plaques of skin. A rash may appear on the face, wrists, hands, feet, scalp, or the back of the knees. Use of creams, lotions, and other moisturizers to keep the skin hydrated can help manage symptoms.

What causes atopic dermatitis vs. eczema?

Atopic dermatitis

The cause of atopic dermatitis is not known, but the disease seems to result from a combination of genetic (hereditary) and environmental factors. There seems to be a basic cutaneous hypersensitivity and an increased tendency toward itching. Evidence suggests that the disease is associated with other so-called atopic disorders such as hay fever (seasonal allergies) and asthma, which many people with atopic dermatitis also have.

In addition, many children who outgrow the symptoms of atopic dermatitis go on to develop hay fever or asthma.

Although one disorder does not necessarily cause another, they may be related, thereby giving researchers clues to understanding atopic dermatitis.

Many of those affected seem to have either a decreased quantity of or a defective form of a protein called filaggrin in their skin. This protein seem to be important in maintaining normal cutaneous hydration.

It is important to understand that food sensitivities do not seem to be a major inciting factor for most cases of atopic dermatitis.

This is an area of active research. Patients with atopic dermatitis seem to have mild immune system weakness.

They are predisposed to develop fungal foot disease and cutaneous staphylococcal infections, and they can disseminate herpes simplex lip infections (eczema herpeticum) and smallpox vaccination (eczema vaccinatum) to large areas of skin.

While emotional factors and stress may sometimes exacerbate the condition, they do not seem to be a primary or underlying cause for the disorder.

Eczema

There are at least 11 distinct types of skin conditions that produce eczema. In order to develop a rational treatment plan, it is important to distinguish them. This is often not easy.

  1. Atopic dermatitis: This health condition has a genetic basis and produces a common type of eczema. Atopic dermatitis tends to begin early in life in those with a predisposition to inhalant allergies, but it probably does not have an allergic basis. Characteristically, rashes occur on the cheeks, neck, elbow and knee creases, and ankles.
  2. Irritant dermatitis: This occurs when the skin is repeatedly exposed to excessive washing or toxic substances.
  3. Allergic contact dermatitis: After repeated exposures to the same substance, an allergen, the body's immune recognition system becomes activated at the site of the next exposure and produces a dermatitis. An example of this would be poison ivy allergy.
  4. Stasis dermatitis: It commonly occurs on the swollen lower legs of people who have poor circulation in the veins of the legs.
  5. Fungal infections: This can produce a pattern identical to many other types of eczema, but the fungus can be visualized with a scraping under the microscope or grown in culture.
  6. Scabies: It's caused by an infestation by the human itch mite and may produce a rash very similar to other forms of eczema.
  7. Pompholyx (dyshidrotic eczema): This is a common but poorly understood health condition which classically affects the hands and occasionally the feet by producing an itchy rash composed of tiny blisters (vesicles) on the sides of the fingers or toes and palms or soles.
  8. Lichen simplex chronicus: It produces thickened plaques of skin commonly found on the shins and neck.
  9. Nummular eczema: This is a nonspecific term for coin-shaped plaques of scaling skin most often on the lower legs of older individuals.
  10. Xerotic (dry skin) eczema: The skin will crack and ooze if dryness becomes excessive.
  11. Seborrheic dermatitis: It produces a rash on the scalp, face, ears, and occasionally the mid-chest in adults. In infants, in can produce a weepy, oozy rash behind the ears and can be quite extensive, involving the entire body.

QUESTION

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What are the symptoms of atopic dermatitis vs. eczema?

Atopic dermatitis

Although symptoms and signs may vary from person to person, the most common symptoms are dry, itchy, red skin.

Itch is the hallmark of the disease.

Typically, affected skin areas include the folds of the arms, the back of the knees, wrists, face, and neck.

The itchiness is an important factor in atopic dermatitis, because scratching and rubbing can worsen the skin inflammation that is characteristic of this disease.

People with atopic dermatitis seem to be more sensitive to itching and feel the need to scratch longer in response.

They develop what is referred to as the "itch-scratch" cycle.

The extreme itchiness of the skin causes the person to scratch, which in turn worsens the itch, and so on. Itching is particularly a problem during sleep, when conscious control of scratching decreases and the absence of other outside stimuli makes the itchiness more noticeable.

Eczema

Almost all patients with eczema complain of itching. Since the appearance of most types of eczema is similar, elevated plaques of red, bumpy skin, the distribution of the eruption can be of great help in distinguishing one type from another. For example, stasis dermatitis occurs most often on the lower leg while atopic dermatitis occurs in the front of the elbow and behind the knee.

What is the treatment for atopic dermatitis vs. eczema?

Atopic dermatitis

If the disease does not respond to mild local over-the-counter treatment then a physician is required. With proper treatment, most symptoms can be brought under control within three weeks.

Topical corticosteroid creams and ointments are the most frequently used treatment. Since many of these are quite potent it will be necessary to have frequent physician visits to assure that the treatment is successful.

Tacrolimus (Protopic) and pimecrolimus (Elidel) are non-steroid topical ointments that contain molecules that inhibit a substance called calcineurin which is important in inflammation. They rather expensive topical medicated creams that are used for the treatment of atopic dermatitis. They are particularly effective in when used on the faces of children since they seem less likely to produce atrophy. These new drugs are referred to as "immune modulators."

Crisaborole (Eucrisa), a recently approved topical treatment for children and adults with mild to moderate atopic dermatitis (AD) which seems to work by inhibiting a different portion of the inflammatory cascade in skin.

Dupilumab (Duxipent) was recently approved by the FDA for treatment of moderate to severe atopic dermatitis in adults. It is an anti-IL-4 antibody that is given by injection twice a month and shows great promise in the control of severe atopic dermatitis.

A newer class of OTC (over the counter) creams have been recently developed which claim to repair and improve the skin's barrier function in both children and adults. They include Atopiclair, MimyX, and CeraVe. These creams may be used in combination with topical steroids and other emollients to help repair the overall dryness and broken skin function.

Additional available treatments may help to reduce specific symptoms of the disease.

Oral antibiotics to treat staphylococcal skin infections can be helpful in the face of pyoderma.

Certain antihistamines that cause drowsiness can reduce nighttime scratching and allow more restful sleep when taken at bedtime. This effect can be particularly helpful for patients whose nighttime scratching aggravates the disease.

If viral or fungal infections are present, the doctor may also prescribe medications to treat those infections.

Phototherapy is treatment with light that uses ultraviolet A or B light waves or a combination of both. This treatment can be an effective treatment for mild to moderate dermatitis in older children (over 12 years old) and adults. Photochemotherapy, a combination of ultraviolet light therapy and a drug called psoralen, can also be used in cases that are resistant to phototherapy alone. Possible long-term side effects of this treatment include premature skin aging and skin cancer. If the doctor thinks that phototherapy may be useful in treating the symptoms of atopic dermatitis, he or she will use the minimum exposure necessary and monitor the skin carefully.

When other treatments are not effective, the doctor may prescribe systemic corticosteroids, drugs that are taken by mouth or injected into muscle instead of being applied directly to the skin. An example of a commonly prescribed corticosteroid is prednisone. Typically, these medications are used only in resistant cases and are only given for short periods of time. The side effects of systemic corticosteroids can include skin damage, thinned or weakened bones, high blood pressure, high blood sugar, infections, and cataracts. It can be dangerous to suddenly stop taking corticosteroids, so it is very important that the doctor and patient work together in changing the corticosteroid dose.

In adults, immunosuppressive drugs, such as cyclosporine, are also used to treat severe cases of atopic dermatitis that have failed to respond to any other forms of therapy. Immunosuppressive drugs restrain the overactive immune system by blocking the production of some immune cells and curbing the action of others.

The side effects of cyclosporine can include high blood pressure, nausea, vomiting, kidney problems, headaches, tingling or numbness, and a possible increased risk of cancer and infections.

There is also a risk of relapse after the drug is discontinued. Because of their toxic side effects, systemic corticosteroids and immunosuppressive drugs are used only in severe cases and then for as short a period of time as possible.

Patients requiring systemic corticosteroids or immunosuppressive drugs should be referred to a dermatologist or an allergist specializing in the care of atopic dermatitis to help identify trigger factors and alternative therapies.

In extremely rare cases, when no other treatments have been successful, the patient may have to be hospitalized. A five- to seven-day hospital stay allows intensive skin care treatment and reduces the patient's exposure to irritants, allergens, and the stresses of day-to-day life. Under these conditions, the symptoms usually clear quickly if environmental factors play a role or if the patient is not able to carry out an adequate skin care program at home.

Eczema

Each type of eczema requires a specific sort of therapy. The easiest eczemas to cure permanently are those caused by fungi and scabies. Allergic contact eczema can be cured if a specific allergenic substance can be identified and avoided.

The treatment of acute eczema where there is significant weeping and oozing requires repeated cycles of application of dilute solutions of vinegar or tap water often in the form of a compress followed by evaporation. This is most often conveniently performed by placing the affected body part in front of a fan after the compress. Once the acute weeping has diminished, then topical steroid (such as triamcinolone cream) applications can be an effective treatment. In extensive disease, systemic steroids may need to be utilized either orally or by an injection (shot).

Mild eczema may respond to compresses composed of tepid water followed by room air evaporation. Chronic eczema can be improved by applying water followed by an emollient (moisturizing cream or lotion). Mild eczema can be effectively treated with nonprescription 1% hydrocortisone cream.

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Medically Reviewed on 1/2/2020
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