Dermatitis

Dermatitis is a general term that describes an inflammation of the skin. There are different types of dermatitis, including seborrheic dermatitis and atopic dermatitis (eczema). Although the disorder can have many causes and occur in many forms, it usually involves swollen, reddened and itchy skin.

There are several types of dermatitis, including: contact dermatitis, a rash that results from either repeated contact with irritants or contact with allergy-producing substances, such as poison ivy; neurodermatitis, a chronic itchy skin condition localized to certain areas of the skin; seborrheic dermatitis, a common scalp and facial condition that often causes dandruff; stasis dermatitis, a skin condition that's caused by a build-up of fluid under the skin of the legs; atopic dermatitis, more commonly known as just eczema or atopic eczema, a chronic itchy rash that tends to come and go; perioral dermatitis, a bumpy rash around the mouth.

Each has distinct signs and symptoms. Common signs and symptoms include: redness, swelling, itching, skin lesions.

Contact dermatitis results from direct contact with one of many irritants or allergens. Common irritants include: laundry soap, skin soaps or detergents, cleaning products. It takes a greater amount of contact with an irritant over a longer time to cause dermatitis than it takes for an allergen. Once you're sensitized to an allergen, just brief exposure to a small amount of it can cause dermatitis. Once you develop sensitivity to an allergen, you typically have it for life.

Neurodermatitis typically develops when something has created an itchy sensation in a specific area of your skin. This irritation may lead you to rub or scratch your skin repeatedly in that area. Common locations include ankles, wrist, outer forearm or arm, and the back of your neck. Possible causes include: dry skin, chronic irritation, eczema, psoriasis.

Seborrheic dermatitis causes a red rash with yellowish and somewhat "oily" scales, usually on the scalp. It's common in people with oily skin or hair, and it may come and go depending on the season of the year. It's likely that hereditary factors play a role in this condition.

Stasis dermatitis can occur when fluid accumulates in the tissues just beneath the skin - typically on your lower legs - due to a sluggish return of blood from the leg veins back to the heart. The extra fluid interferes with your blood's ability to nourish your skin and places extra pressure against your skin from underneath.

Atopic dermatitis often occurs with allergies and frequently runs in families in which members have asthma or hay fever. It usually begins in infancy and may vary in severity during childhood and adolescence. It tends to become less of a problem in adulthood, unless you're exposed to allergens or irritants in the workplace.

Perioral dermatitis may be a form of the skin disorder rosacea, adult acne or seborrheic dermatitis, involving the skin around the mouth or nose.