What does eczema look like? Signs and diagnosis

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 like it. This guide describes what atopic eczema (also called atopic dermatitis), the most common type, looks like at different ages and on different skin tones, and how a doctor confirms it. For an overview of the whole condition, start with the complete guide to eczema.

The itch comes first

The American Academy of Dermatology (AAD) says atopic dermatitis is often called "the itch that rashes." It tends to start suddenly with itchy skin, and scratching the itchy skin often causes a rash. MedlinePlus, the health site of the US National Library of Medicine, says the same: itching may start even before the rash appears.

The US National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) calls itching the most common symptom of atopic dermatitis and says it can be severe. Scratching leads to more redness, swelling, cracking, clear fluid leaking from the skin, crusting and scaling. Many of the visible signs of eczema come from scratching.

The common signs

The NHS says atopic eczema can make your skin:

• itchy
• dry, cracked, crusty, scaly or thickened
• red, white, purple or grey, or lighter or darker than the skin around it, depending on your skin tone
• blister or bleed

The AAD adds more signs: skin that feels warm and swollen, scratch marks, raw skin from scratching, bumps or rashes that leak fluid, and blisters that ooze and then crust over. It also says that after healing, skin may be lighter or darker where the eczema was.

Eczema changes over time. The NHS says there are usually times when symptoms get worse, called flare-ups, and times when they are better. The AAD says flare-ups can appear in one area while another area heals, and they can come back in the same place again and again. Over the years, skin that is rubbed or scratched a lot can become thick, scaly and leathery, and it can crack. The AAD says thickened skin tends to itch most of the time.

How eczema looks on different skin tones

Eczema looks different on different skin tones.

On lighter skin, the AAD describes a red rash, and the NHS describes pink or red patches. On darker skin, the picture changes. The AAD lists small, rough bumps and dark brown, purple or grey areas of skin as signs that are more common on darker skin tones. The NHS photo descriptions show atopic eczema on dark brown skin as grey, white and dry areas, and as skin that is darker and lighter than the skin around it, cracked and thickened. NIAMS says people with darker skin tones often get darkening or lightening of the skin where it is inflamed.

Where eczema appears can differ too. NICE, the UK body that writes guidance for doctors, tells doctors that in Asian, Black Caribbean and Black African children, atopic eczema can affect the outer sides of joints (such as the front of the knees) instead of the skin creases, and that round patches or patterns around hair follicles may be more common. The AAD says children with darker skin tones often get patches on the fronts of the knees, the elbows and the backs of the hands.

Where eczema appears at each age

The place eczema shows up tends to change as a person grows. This table draws on NIAMS and the AAD.

Age	Where atopic eczema often appears	What it often looks like
Babies, up to age 2	Face (often the cheeks), forehead, scalp, and skin around joints that bend	A red rash that may ooze when scratched; on darker skin, small bumps and darker patches
Children, age 2 to puberty	Bends of the elbows and knees, neck, wrists and ankles	A red, thickened rash that may ooze or bleed when scratched
Teens and adults	Hands, neck, bends of the elbows and knees, skin around the eyes, ankles and feet	A red to dark brown scaly rash that may bleed and crust; thick skin where it has lasted for years

NIAMS says it is rare for atopic eczema to appear in the nappy (diaper) area of a baby, which some parents worry about. The AAD says adults are more likely than children to have eczema on their hands, and that for some adults the hands are the only place it appears. Adults are also more likely to have it around the eyes, often as thickened skin that is darker than the skin around it. The guide to eczema on the face covers the face and eyelids in more detail.

MedlinePlus adds that in adults the rash may be limited to the hands, the eyelids or the genitals, and that during a bad outbreak it can appear anywhere on the body.

Signs that need a doctor quickly

Some changes mean the skin may be infected. The NHS says to ask for an urgent appointment, or to call NHS 111 in the UK, if you or your child have atopic eczema and:

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

The NHS says these can be signs that eczema is infected, or of a more serious condition called eczema herpeticum. Eczema itself cannot be caught, but some of these infections can spread, as the guide is eczema contagious? explains. The AAD says yellow or golden crusts often mean a staph infection, a common bacterial infection. It describes eczema herpeticum as a serious infection caused by the cold sore virus, with dome-shaped blisters and bumps, fever, tiredness and swollen glands. In babies, children and anyone with a weak immune system, the AAD says eczema herpeticum can be life-threatening and needs immediate medical care.

Conditions that can look like eczema

Several skin conditions look like eczema, and some of them need different treatment:

• Psoriasis and fungal infections. The NHS says psoriasis and fungal infections, such as ringworm and athlete's foot, can cause sore, itchy patches or blisters on the hands and feet that look like pompholyx, a type of eczema.
• Ringworm and discoid eczema. The NHS says the centre of a discoid eczema patch sometimes clears and leaves a ring of discoloured skin that can be mistaken for ringworm.
• Seborrheic dermatitis. The AAD says this scaly rash on oily areas like the scalp and face can appear in many ways and sometimes looks like another condition.
• Other types of eczema. The AAD says nummular eczema, contact dermatitis and neurodermatitis also cause itchy patches, and each needs different treatment.

Eczema is also linked to asthma, allergies and some autoimmune diseases, which the guide is eczema an autoimmune disease? covers. The guide to types of eczema explains how each type differs, and eczema vs dry skin covers the most common question of all.

How a doctor confirms eczema

Doctors diagnose eczema mainly by looking at the skin and asking questions. The AAD says a board-certified dermatologist examines the skin and asks questions, and that a skin exam plus information about your health and symptoms may be all the dermatologist needs to make a diagnosis. Sometimes the doctor takes a skin biopsy, which means removing a small piece of skin to look at under a microscope. The AAD says a biopsy can also help the dermatologist choose the best treatment.

NIAMS lists what a doctor may ask about: your family history of allergies, whether you have hay fever, asthma or food allergies, sleep problems, past treatments, and contact with irritants such as soaps, detergents, perfumes, cosmetics and cigarette smoke. NIAMS says the doctor may order blood tests to check for other causes of the rash, and may need to see you several times to make an accurate diagnosis. MedlinePlus says allergy skin testing can help some people, such as those with eczema that is hard to treat or a rash that appears only after contact with a certain chemical.

For children under 12, NICE tells UK doctors to diagnose atopic eczema when a child has an itchy skin condition plus 3 or more other signs from a set list, such as rash in the skin creases, a history of dry skin, or asthma or hay fever.

NIAMS says family doctors, internists, pediatricians, dermatologists and allergists can all diagnose and treat atopic dermatitis.

Getting ready for the appointment

The AAD suggests finding the answers to a few questions before you go:

• Do any of your blood relatives have atopic dermatitis, asthma or hay fever?
• What are your symptoms, and when did they begin?
• Does anything make the symptoms worse or better?
• Where do rashes, dryness and itch appear on your skin?

The AAD says eczema comes and goes, so your skin may not be at its worst on the day you see the doctor, and that this is okay. Once a doctor confirms eczema, the guide on how eczema is treated describes what a doctor may offer next.