Eczema is a common skin condition hallmarked by itchy and inflamed patches of skin, particularly on faces in infants, as well as inside the elbow and behind the knees of children, teenagers, and adults. Also commonly known as atopic dermatitis, eczema is caused by an overactive immune system. The skin condition is more common in babies and young children, but eczema can also occur in adults. Up to 20 percent of children and one to three percent of adults develop atopic dermatitis, according to the American Academy of Dermatology (AAD). Atopic dermatitis crops up during the first year of life for 60 percent or more sufferers. At least 80 percent have the inflammatory skin condition before the age of five. In rare cases, atopic dermatitis can first appear during puberty or adulthood. It affects males and females equally.
When people refer to eczema, they generally mean atopic dermatitis, which is the common and chronic form of eczema. Other types of eczema include:
Contact dermatitis occurs when certain irritants come in contact with the skin and cause inflammation—namely, burning, itching or redness. When the irritant is removed, the inflammation goes away.
Dyshidrotic dermatitis affects fingers, palms of the hand, and soles of the feet, causing itchy, scaly patches of skin that flake constantly or become red, cracked and painful. The condition is twice as common in women than in men.
Nummular dermatitis causes dry, round patches of skin in the winter months. It can affect any part of the body, but commonly appears on the lower leg. It is more common in men.
Seborrheic dermatitis leads to itchy, red, scaly rashes in different locations on the body, particularly the scalp, eyebrows, eyelids, sides of the nose, and behind the ears.