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Overview: Eczema

Last Update: February 11, 2021; Next update: 2024.

Introduction

Eczema is a chronic, non-infectious skin condition. The main symptom is a very itchy rash. Eczema is common in children. It often gets better over time and it may also go away for a while or disappear altogether. Eczema that is related to an allergy is called atopic eczema or atopic dermatitis.

Eczema can greatly affect your quality of life. The itching can be especially bad, making it difficult to concentrate and sleep well. Many people who have eczema are ashamed of the visible rash. But it can usually be managed by taking good care of your skin, using medication and avoiding things that trigger the disease.

At a glance

  • Eczema causes your skin to become inflamed and very itchy.
  • The rashes aren't contagious, and they usually come and go in bouts (“flare-ups”).
  • Taking good care of your skin and avoiding irritants can help prevent flare-ups.
  • Acute rashes can usually be treated effectively with steroid ointments or creams.
  • Side effects are very rare when these topical steroids are used correctly.

Symptoms

The main symptom of eczema is unbearable itching. The severity of the rash that eczema causes depends on the stage of the condition:

  • During an acute rash, the skin is reddish and very itchy. Blisters may form on the inflamed areas of skin. These can easily break open and then weep (leak liquid).
  • The rash gradually gets better after the acute phase. The skin becomes dry and peels off.
  • Over time, the affected skin may get thicker, rougher and crack.

You can also have acute and less acute rashes on different parts of your body at the same time.

Eczema usually comes and goes in bouts (flare-ups). This means that the symptoms sometimes get better and sometimes get worse. They can also go away completely for a while. The skin is only rarely permanently inflamed.

In babies, eczema mainly appears on the cheeks and the outer surfaces of the arms and legs and – less commonly – on the back, tummy and chest. In children, teenagers and adults, it mainly affects the hollows of the knees, the elbows and the back of the neck. The itchy rash may also occur on the palms of the hands and the soles of the feet. It rarely affects the face.

Illustration: Eczema in children and adults: Commonly affected areas of skin- as described in the article

Eczema in children and adults: Commonly affected areas of skin

Causes

The skin consists of three layers:

  • Outer layer (epidermis)
  • Middle layer (dermis)
  • Inner layer (subcutis)

The outer layer has different layers too: the basal layer, the spinous or prickle-cell layer, and the corneal or horny layer (enlarged in the diagram below). The corneal layer – the visible part of the skin – protects the body from germs. It renews itself constantly as new cells grow from the basal layer.

Illustration: Healthy skin and skin affected by eczema - as described in the article

Left: Healthy skin, right: Skin with eczema

In people with eczema, the corneal layer doesn't provide enough protection because it is damaged by the inflammation in the skin. That allows irritants, germs and substances that trigger allergies (allergens) to enter the body.

Eczema can also be caused by other things, including disorders of the immune system or the microorganisms ("bugs") living on the skin, as well as changes in certain genes – especially in one called the FLG gene. This gene inhibits the production of filaggrin, a protein that plays an important role in the growth of the outer layer of skin. Because there isn't enough filaggrin, the balance of fats in the skin changes, causing the skin to lose a lot of moisture. The significance of the different factors and how they affect each other isn't fully understood.

In about 30-40% of all people with eczema, it is related to an allergy (atopic eczema). They often have more severe symptoms, as well as hay fever or allergic asthma.

In atopic eczema, the immune system reacts to allergens by producing antibodies that cause inflammations in the skin. These antibodies can be detected in the blood. Allergens that sometimes play a role in eczema include dust mites, pollen and foods such as milk, eggs, nuts or fish.

The skin may also be irritated by environmental factors or other substances that are not allergens. Examples include rough fabrics (such as scratchy wool) in contact with the skin, cigarette smoke and extreme heat or cold.

Risk factors

Genes play a major role in someone's risk of developing eczema. But other factors have an influence as well. Eczema has become more common in recent decades, which shows that genes can't be the only explanation. Doctors think that pollution and increased hygiene also play a role.

This theory is based on the observation that eczema is less common in children who have many siblings or a dog, or who spent time at day care from an early age. It is thought that these children are exposed to germs at an earlier age and that this helps to train their immune system.

Prevalence and outlook

About 10 to 20% of all children and an estimated 2 to 5% of all adults have eczema. Eczema usually starts at a very young age, typically between the third and sixth months of life. It can also develop later. But it is quite rare for eczema to develop after the age of five years.

A rash on a baby's scalp (sometimes called "cradle cap") may be an early sign, but it doesn't necessarily mean that the child will develop eczema.

The further course of eczema depends on the age at which it first develops, among other factors. Children who develop eczema under the age of twelve months often grow out of it relatively quickly: Only half of them will still have it after three years.

Eczema is often more persistent in children who develop it between the ages of two and five years. It is estimated that eczema gets much better or goes away again in more than 80% of all affected children about ten years after it first appears. But some people still have it as teenagers.

Eczema can disappear for a while and then return in adulthood, most commonly on the hands. It is rare to first develop eczema as an adult.

Effects

A type of bacteria called Staphylococcus aureus sometimes causes an infection in the areas of skin affected by eczema. These bacteria can also be found on the skin of people who don't have eczema. They are usually harmless. But if they cause an infection, they can make eczema worse. That makes the skin turn very red, and it may weep (leak fluid), resulting in yellowish scabs. If the infection spreads, it will usually have to be treated with antibiotics.

When skin has changed and become inflamed due to eczema, it is also easier for herpes viruses to spread. Herpes infections usually occur on the face. Small blisters filled with clear fluid form and then burst a short time later. The blisters leave behind small dot-like crusts. The skin can become very sore and there may also be other symptoms like fever or tiredness. If a herpes infection spreads to other areas of skin, it's important to see a doctor quickly.

Allergic eczema may be associated with hay fever or asthma. About one third of all children who have eczema also develop asthma or hay fever by the time they turn five.

Diagnosis

Eczema is diagnosed by doing a physical exam. If you have an itchy rash on the parts of your body that are typical for eczema in a person of your age, and it lasts or keeps coming back for several months, a doctor will diagnose you with eczema. Other possible conditions such as psoriasis will be ruled out at the same time. Eczema is sometimes confused with seborrheic dermatitis, especially in young babies. But that condition hardly itches, and clears up on its own after a few weeks or months.

If someone is believed to have allergic eczema, an allergy test might be done – either by testing their blood or doing a skin prick test. The blood is tested for specific antibodies that the body produces in response to allergens.

If the test results are normal, it's quite certain that the person doesn't have an allergy. Abnormal results are more difficult to interpret: They confirm that the body is overly sensitive but don't say anything about whether this reaction or the severity of the symptoms have anything to do with the eczema. That's why it's important to, for instance, use what is called a "challenge" test to find out whether the skin actually reacts to the allergen. Under the supervision of a doctor, you eat or drink a food that may possibly trigger an allergy in order to see how your body reacts.

Because these allergy tests don't lead to clear conclusions, it's not a good idea to test for all different kinds of substances if there's no good reason to believe that they might be affecting your eczema.

Prevention

The risk of developing eczema is mostly hereditary – in other words, it runs in families. But it's never really possible to say exactly why a child has developed eczema because there are so many different factors involved. No treatments have been proven to prevent eczema.

In large and good-quality studies, using skin care products in a child's first year of life wasn't found to lower babies' risks of developing eczema. Neither did early exposure to foods like peanuts, milk, eggs and wheat.

Many other approaches and products are claimed to lower the risk of developing eczema, but it's not clear whether they work. These include the use of vitamins (for example vitamin D), omega-3 fatty acids, certain types of diets, measures to reduce dust mites and avoiding certain foods during pregnancy.

Taking dietary supplements containing probiotic bacteria is the only thing that has been proven to prevent eczema, but the evidence is weak.

Breastfeeding possibly lowers the risk of eczema somewhat. The research results aren't clear here, though. Despite this uncertainty, the World Health Organization (WHO) recommends that women fully breastfeed their babies for the first six months of their life if possible and then offer them both solid foods and breast milk. This is because breastfeeding strengthens the bond between mother and child, and offers other health benefits for babies.

It's also a good idea to have the child vaccinated against illnesses like chickenpox because those kinds of illnesses can be more severe in children who have eczema.

Treatment

Eczema is a chronic condition – in other words, there is no cure. But good skin care and medication can keep the itching and rash at bay. The main treatment options are:

  • Basic treatment with lipid-replenishing and moisturizing products (emollients): These products are generously applied to the skin at least twice a day to stop it from drying out. This relieves symptoms like itching, protects the skin from germs and irritants, and prevents flare-ups.
  • Avoiding irritants: The skin might be irritated by certain things, such as scratchy wool, cleaning agents and particular contact allergens (in people who have an allergy). It's helpful to avoid these kinds of irritants as much as possible. Extreme temperatures can affect the skin too.
  • Steroid creams: Eczema flare-ups are treated with steroid creams. They can very effectively reduce the itching and inflammation. "Weekend treatment" (intermittent treatment) is one option for people who have frequent flare-ups. This involves applying a steroid cream to the affected areas of skin on two days a week in addition to the basic treatment. This approach can significantly reduce the frequency of flare-ups.
  • Pimecrolimus and tacrolimus: Pimecrolimus and tacrolimus are two other medicines that can be used to treat eczema. These two medicines are applied to the skin in a cream or ointment, and can be used in the long-term treatment of sensitive skin on the face and neck, for instance.

Light therapy (phototherapy) with UV light is an option if these treatments aren't effective enough, for example if the eczema is very severe or covers large areas of skin. If that doesn't provide enough relief, then tablets can be taken to suppress certain immune system reactions.

Allergy medicines (antihistamines) are sometimes used to relieve itching too. But research has now shown that they don't relieve the symptoms of eczema.

People often try out plant-based products or dietary supplements, such as evening primrose oil, borage oil, vitamins and zinc. There is no scientific proof that these work either. That's also true of other treatments, like laser therapy or allergen immunotherapy. So they aren't recommended by medical societies.

Everyday life

It's easy to underestimate how difficult eczema can make your life. You need to be patient to deal with the daily challenges associated with eczema and to find the right treatment for you. But many people manage to get their eczema under control.

The itching can be especially unbearable. Scratching is a normal reaction, but it can increase the likelihood of complications and make the itching even worse. Most people who have eczema know that it's better to be careful because superficial scratches can become inflamed. But this is easier said than done. So there's no need to feel guilty if you do end up scratching your skin once in a while. Keeping children's nails cut short can help to stop them from scratching too much.

Eczema can also be hard on children, and some days will be testing for both the child and their parents. But periods of severe symptoms are usually followed by periods of milder symptoms. And the odds are that the eczema will improve on its own or even disappear altogether as the children grow up.

Parents who have a child with eczema may feel unable to cope and helpless from time to time. Worrying about your child, keeping up the skin care routine, countless visits to the doctor and sleepless nights can be a great burden. Special eczema education courses have been developed to help parents, children and teenagers. The courses provide information on the treatment options and ways to avoid irritants. They also offer tips on coping with eczema in everyday life. In Germany, these courses typically involve a total of six two-hour sessions held on a weekly basis. The costs are covered by many of the health insurers in Germany. If you have severe eczema, outpatient or inpatient rehabilitative care may be considered too.

Parents and children often feel discouraged by how others react to eczema. Some people don't know much about the disease, which can easily lead to misunderstandings. For instance, they might think it's contagious or that the child's parents have been neglecting him or her. To prevent that from happening, it can be helpful to address the possible misunderstandings and stereotypes by talking openly about the condition and its effects. Support groups are one way to share your experiences with other parents in similar situations.

Further information

There are many sources of support in Germany for people with eczema. These include support groups and information centers. Support services are often organized quite differently from region to region, though. Our list of places to contact may help you to find and make use of the help you need.

When people are ill or need medical advice, they usually go to see their family doctor first. Read about how to find the right doctor, how to prepare for the appointment and what to remember.

Sources

© IQWiG (Institute for Quality and Efficiency in Health Care)
Bookshelf ID: NBK279399

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