The Facts

Specialists themselves disagree on which diseases should be considered eczema. Simply put, eczema is an inflammation of the skin that's not caused by infection. It's also known as dermatitis. The condition may be temporary or chronic, mild or, in rare instances, life-threatening. In life-threatening cases:

• it is severe enough to cause complications, such as cellulitis; or
• an affected person also contracts the herpes simplex virus; or
• an affected person has a violent allergic reaction caused by contact dermatitis.

Contact dermatitis is the most common type of skin inflammation. It's a temporary reaction to an irritant or an allergen. An example is poison ivy.

Atopic dermatitis is the prevalent form of chronic eczema. A genetically inherited condition, it tends to run in families who also suffer from hay fever and asthma. Atopic dermatitis will affect about 10% of Caucasians and Asians at some point in their lives.

Seborrhea is eczema of the scalp. In adults, mild seborrhea is known as dandruff. In babies, it tends to look more severe, and is called cradle cap.

Nummular eczema normally affects older adults, and its cause is unknown. Round patches of scaly, inflamed skin may appear anywhere on the body. Winter is the peak period for this condition. It tends to strike dry skin.

Varicose eczema (or gravitational eczema) affects the lower legs of older adults. It is basically a poor circulation problem, usually due to blood not being able to get out of the legs well. It is caused by varicose veins.

Lichen simplex chronicus is a non-allergic itch, which often appears in times of stress. The disease is prolonged and sometimes spreads if you scratch.

Causes

Genetic inheritance plays a major role in most forms of eczema. Atopic dermatitis is an inherited oversensitivity of the immune system. Genes play a role in allergies, too, though it usually takes prolonged exposure to a given allergen before it becomes a nuisance. There are some chemicals, of course, that will irritate any skin. Harsh irritants can give anyone a temporary bout of contact dermatitis.

Seborrhea appears to be linked to the yeast called Pityrosporum ovale, which inhabits most human scalps. It's a mystery why some people are so much more severely affected by this organism than others.

Varicose eczema is caused by poor circulation in the lower extremities. Fluid builds up in the capillaries due to raised blood pressure. This causes inflammation of the skin.

Lichen simplex is caused by excessive scratching of minor itches.

There are also general risk factors than will aggravate any kind of eczema. These include harsh soap, rubber gloves, wool, very hot water, and emotional stress.