Health Topics A-Z

What Is Dermatitis?

Dermatitis simply means skin inflammation, but it embraces a range of ailments. In most cases the early stages are characterized by dry, red, itchy skin, although acute attacks may result in crusty scales or blisters that ooze fluid. Since many things can irritate the skin, a doctor will try to narrow the diagnosis to a specific category of dermatitis, even though treatment is similar for most types of skin irritation and inflammation.

The categories of dermatitis:

Contact dermatitis typically causes the skin to develop a pink or red rash, which may or may not itch. Pinpointing the exact cause of contact dermatitis can be difficult. Among plants, the leading culprits are poison ivy, poison oak, and poison sumac, although contact with certain flowers, herbs, fruits, and vegetables irritate some people.

Common chemical irritants include detergents, soaps, chlorine, some synthetic fibers, nail polish remover, antiperspirants, and formaldehyde (found in permanent-press fabrics, polishes, artificial-fingernail adhesive, particle board, and foam insulation). Wearing rubber gloves, unwashed new clothes, or plated jewelry can also cause contact dermatitis. The inflammation is frequently caused by cosmetics, perfumes, hair dyes and skin-care products.

Nummular dermatitis consists of distinctive coin-shaped red patches that are most commonly seen on the legs, hands, arms and torso. It is more common in men than women and the peak age of onset is at 55-65 years of age. Living in a dry environment or taking very hot showers can cause this condition, as can stress and other skin disorders.

Atopic dermatitis, or eczema, causes the skin to itch, scale, swell and sometimes blister. Eczema usually runs in families and is often associated with allergies, asthma, and stress.

Seborrheic dermatitis consists of greasy, yellowish, or reddish scaling on the scalp and other hairy areas, as well as on the face or genitals, and in skin creases along the nose, under the breasts, and elsewhere. It is caused by an overproduction and blockage of oil glands. This condition is called cradle cap in infants and is likely related to hormonal changes affecting the glands. It may be aggravated by stress.

Stasis dermatitis is caused by poor circulation and can happen in people with varicose veins, congestive heart failure, or other conditions. Veins in the lower legs fail to return blood efficiently, causing pooling of blood and fluid buildup and edema. This leads to unhealthy skin growth and irritation, especially around the ankles.