What is eczema? Symptoms, causes and treatment

Eczema is a group of skin conditions that make skin dry, itchy and inflamed. Only a doctor can confirm that a rash is eczema, because several other conditions look similar and need different treatment. This guide explains what eczema is, who gets it, what it looks like, what causes it, how a doctor diagnoses and treats it, and what to expect over time. Each section links to a longer guide on that topic.

What eczema is

The American Academy of Dermatology (AAD) says eczema refers to a group of conditions that cause rashes, itchiness and excessively dry skin. MedlinePlus, the health site of the US National Library of Medicine, says eczema is also called dermatitis. The two words name the same group.

The most common type is atopic dermatitis, also called atopic eczema. The NHS describes it as a common skin condition that causes itchy skin. The US National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) calls it a chronic, or long-lasting, disease that causes inflammation, redness and irritation of the skin. The word "atopic" means linked to allergies, according to MedlinePlus Genetics. When people say "eczema" without naming a type, they usually mean atopic eczema, and this guide does too unless it says otherwise.

Other types include contact dermatitis, discoid (nummular) eczema, pompholyx (dyshidrotic eczema), varicose (stasis) eczema and seborrheic dermatitis. The guide to types of eczema describes each one.

Who gets eczema

Eczema is common. The AAD says atopic dermatitis affects 1 in 10 Americans. MedlinePlus Genetics says it affects 10 to 20 percent of children and 5 to 10 percent of adults. The AAD's 2026 guideline for children says eczema affects up to 25 percent of children worldwide.

It usually starts early. The AAD says atopic dermatitis often appears between 2 months and 5 years of age, and most people who get it do so by age 5. It can also begin at puberty or in adult life, with a peak for adult-onset eczema in a person's 50s.

Some people are more likely to get it. The NHS says you are more likely to have atopic eczema if one or both of your parents have it, or if you or a close relative has asthma or hay fever. The AAD says that in the United States, Black children are twice as likely as white children to develop it, and that people in cities get it more often than people in rural areas.

What eczema looks like

Itch comes first. NIAMS says itching is the most common symptom and can be severe. The AAD calls atopic dermatitis "the itch that rashes," because scratching the itchy skin often causes the rash.

The NHS says atopic eczema can make skin dry, cracked, crusty, scaly or thickened. It can look red, white, purple or grey, or lighter or darker than the skin around it, depending on skin tone, and it can blister or bleed. The AAD says small, rough bumps and dark brown, purple or grey patches are more common on darker skin.

Where it appears changes with age. The NHS says it is common on the elbows, knees and hands, and on the face in babies and toddlers. NIAMS says children often get it in the bends of the elbows and knees, while teens and adults often get it on the hands, neck, skin around the eyes, ankles and feet.

Eczema comes and goes. The NHS says there are usually times when symptoms get worse, called flare-ups, and times when they are better. The guide to what eczema looks like shows the signs by age and skin tone, and the guide to eczema on the face covers the face and eyelids.

What causes eczema

Nobody knows the exact cause. NIAMS says researchers know that genes, the immune system and the environment all play a part.

• The outer layer of the skin. The AAD says the outer layer of skin in people with atopic eczema has gaps that let water out and let irritants and germs in. This dries the skin and causes inflammation.
• Genes. MedlinePlus Genetics names the FLG gene as the strongest known genetic link. It makes a protein that helps skin hold water.
• The immune system. NIAMS says the immune system sometimes becomes confused and overactive, which creates inflammation in the skin.
• The environment. NIAMS lists tobacco smoke, some air pollution, fragrances and other ingredients in skin products and soaps, and skin that is too dry.

Allergies often come with eczema. MedlinePlus says people with atopic dermatitis often test positive on allergy tests, yet allergies do not cause it. The guide to what causes eczema explains each cause. Many people also ask whether eczema is an autoimmune disease, which has its own guide: is eczema an autoimmune disease?

Is eczema contagious?

Eczema is not contagious. The NHS says atopic eczema is not contagious, so you cannot catch it or spread it. Skin with eczema can pick up infections, though, such as staph bacteria or the cold sore virus, and those germs can spread. The guide is eczema contagious? explains the difference.

What makes eczema flare

A trigger is anything that makes eczema that is already there get worse for a while. The NHS lists soap, washing detergent, some fabrics, pets, pollen, house dust mites and certain foods, heat or changes in temperature, skin infections, stress and hormonal changes such as pregnancy. The AAD adds cold weather, wool, fragrance and harsh detergents. Different people have different triggers. The guide to eczema flare-up triggers explains how to find yours.

How a doctor confirms eczema

There is no single test for eczema. The AAD says a dermatologist examines the skin and asks questions, and that a skin exam plus information about your health and symptoms may be all that is needed. Sometimes the doctor takes a small skin sample, called a biopsy. NIAMS says a doctor may order blood tests to rule out other causes, and may need several visits to be sure.

Other rashes look like eczema, such as psoriasis and fungal infections like ringworm. Dry skin is the most common mix-up. The guide to eczema vs dry skin explains how to tell them apart. NIAMS says family doctors, pediatricians, dermatologists and allergists can all diagnose and treat atopic dermatitis.

How eczema is treated

Treatment controls eczema. The NHS says the main treatments are moisturizers, which it calls emollients, and steroid creams, which doctors call topical corticosteroids. The AAD says a plan usually includes skin care, avoiding triggers and medicine applied to the skin.

When those are not enough, the AAD says a dermatologist may offer non-steroid creams, light treatment, or medicines that work throughout the body, given as pills or injections. The AAD says the first of these medicines was approved by the FDA in 2017, and its guidelines strongly recommend several of them for moderate to severe eczema. The guide on how eczema is treated describes each option a doctor may offer. Keep to the plan your doctor gives you. The NHS says not to stop a steroid medicine without talking to your doctor first.

Daily care is part of every plan. The NHS says to apply moisturizer at least twice a day and keep going even when eczema improves, and to wash with a moisturizer instead of soap. The AAD advises short, warm baths or showers and moisturizer on damp skin straight afterward. The guide to moisturizing and bathing for eczema covers the steps.

Can eczema be cured?

Atopic eczema has no cure at present. The NHS says atopic eczema cannot be cured, but treatment can help manage the symptoms. The AAD says it can be controlled with proper treatment. Some types can clear completely: the NHS says contact dermatitis usually clears up once its cause is found and avoided. The guide can eczema be cured? looks at this in depth, including why remedies that promise a cure need care.

Does eczema go away?

Many children grow out of it. NIAMS says atopic dermatitis goes away before the teenage years for many children. A 2016 review in the Journal of the American Academy of Dermatology found that 80 percent of childhood cases did not last 8 years after diagnosis. In adults, MedlinePlus says eczema is usually a long-term or returning condition, and the AAD says eczema that went away in childhood can come back years later, often milder. The guide does eczema go away? covers children and adults.

Living with eczema

Eczema affects more than the skin. The AAD says many people with atopic dermatitis feel anxious, depressed or both, often because of itch, pain and poor sleep. The NHS says that if eczema affects your mental health, you may be referred to a mental health specialist. NIAMS suggests stress management, support from family and friends, and counseling for anyone who feels overwhelmed.

When to see a doctor

See a doctor if you think you or your child have eczema, or if treatment is not helping, the NHS says. Any rash on a baby should be checked by a doctor. Ask for an urgent appointment if eczema:

• is blistered, crusty, leaking fluid or has spots filled with pus
• is painful, swollen or feels warm
• suddenly gets worse or gets bigger
• comes with a high temperature or feeling unwell

The NHS says these can be signs of infection or of eczema herpeticum, a serious infection with the cold sore virus. The AAD says eczema herpeticum can be life-threatening in babies and children and needs immediate medical care.