Eczema is a general term for a group of conditions that cause the skin to become inflamed, red, dry, and itchy. In some cases, a rash might develop in one area or over the entire body. One of the most common forms of eczema is atopic eczema, also called atopic dermatitis.

What are the symptoms of eczema?

Eczema might look different from person to person, and it might appear on different parts of the body. In adults, eczema most often develops on the hands and elbows, and in "bending" areas such as the inside of the elbows and back of the knees. In young children, eczema most often develops on the elbows, knees, face, neck, and scalp.

Common symptoms of eczema include:

• Itchiness
• Skin redness
• Dry, scaly, or crusted skin that might become thick and leathery from long-term scratching
• Formation of small, fluid-filled blisters that might ooze when scratched
• Infection of the areas where the skin has been broken

What causes eczema?

The exact cause of eczema is not known. However, it appears to run in families and occurs more often in people who have a personal or family history of asthma, hay fever, and other allergies, suggesting a genetic (hereditary) factor in the development of eczema. In addition, eczema symptoms tend to flare up or worsen when the person is exposed to certain substances and situations, called triggers. Eczema triggers might include:

• Skin irritants — Irritants are substances that cause burning, itching, or redness. They include harsh soaps, chemicals, perfumes, and skin care products that contain alcohol. Some fabrics, such as wool, and tight clothing can also irritate the skin.
• Allergens — Allergens are substances that trigger an allergic reaction, which may include sneezing, itching, watery eyes, and a stuffed or runny nose. Some allergens, such as pollens, pet hair or dander (dried bits of saliva and skin), and even certain foods — such as eggs, wheat, nuts, and milk products — can also trigger or worsen eczema symptoms.
• Climate and environment — Low humidity (dry air) can cause the skin to become dry and itchy. Heat and high humidity cause sweating, which can make itching worse.
• Stress — Stress has been shown to trigger flare-ups in some people with eczema. In addition, it may be more difficult to control scratching irritated skin when under stress.