Eczema, also called atopic dermatitis, is a common skin condition marked by itchy and inflamed patches of skin.

It’s often seen in babies and young children, appearing on the faces of infants. But eczema can come in a variety of types in children, teens, and adults. Read on to learn what causes the skin condition and how to treat its symptoms.

The main symptom of eczema is itchy, dry, rough, flakey, inflamed, and irritated skin. It can flare up, subside, and then flare up again.

Eczema can occur anywhere but usually affects the arms, inner elbows, backs of the knees, or head (particularly the cheeks and the scalp). It’s not contagious, and, in some cases, becomes less severe with age.

Other symptoms include:

intense itching

red or brownish-gray patches

small, raised bumps that ooze fluid when scratched

crusty patches of dried yellowish ooze, which can signal infection

thickened, scaly skin

Scratching eczema further irritates and inflames the skin. This can cause infections that must be treated with antibiotics.

When people refer to eczema, they usually mean atopic dermatitis, which is characterized as dry, itchy skin that often appears with a red rash. This is the most common and chronic type of eczema.

Other types include:

Contact dermatitis

Contact dermatitis is caused by contact with irritants. Burning, itching, and redness occur. The inflammation goes away when the irritant is removed.

Dyshidrotic dermatitis

Dyshidrotic dermatitis affects fingers, palms of the hands, and soles of the feet. It causes itchy, scaly patches of skin that flake or become red, cracked, and painful. The condition is more common in women.

Nummular dermatitis

Nummular dermatitis causes dry, round patches of skin in the winter months. It usually affects the legs. It’s more common in men.

The cause of eczema is not fully understood.  However it is believed to be related to an overactive immune system that responds aggressively when exposed to irritants.

Eczema is sometimes caused by an abnormal response to proteins that are part of the body.

Normally, the immune system ignores proteins that are part of the human body and attacks only the proteins of invaders, such as bacteria or viruses.

In eczema, the immune system loses the ability to tell the difference between the two, which causes inflammation.

An eczema flare-up is when one or more eczema symptoms appear on the skin.

Common triggers of eczema flare-ups include:

• chemicals found in cleaners and detergents that dry out the skin
• rough scratchy material, like wool
• synthetic fabrics
• raised body temperature
• sweating
• temperature changes
• sudden drop in humidity
• stress
• food allergies
• animal dander
• upper respiratory infections

Several factors can increase your risk of developing eczema.

Eczema is more common in children who suffer from asthma or hay fever, or adults who develop these conditions later, usually before the age of 30.

People with family members who have eczema are also at higher risk of developing the condition.