Eczema is the name for a group of inflammatory skin conditions, the most common type of which is atopic eczema. Atopic eczema (also known as atopic dermatitis) causes red, dry and itchy skin. It particularly affects skin creases such as those on the backs of knees, front of the elbows and around the neck. Atopic eczema is a common condition, affecting between 15-20% of children and 2-10% of adults. The term ‘atopic’ refers to a predisposition towards having an allergic reaction. People with atopic eczema are also more likely to develop asthma and hayfever.
The main symptoms of atopic eczema include:
- dry skin
- red and inflamed skin
Itchiness is the predominant symptom of atopic eczema – if you do not have itching, it is very unlikely that you have atopic eczema. Continued scratching of itchy skin may cause the skin to thicken.
Inflammation of the skin in atopic eczema can sometimes cause blisters to develop and the skin may begin to weep. Inflamed areas of skin may also become infected. Signs of infection include a high temperature, weeping of the skin and yellow-white spots or a yellow-crust forming on the skin surface.
Eczema is considered to be a relapsing, remitting condition. This means that symptoms tend to flare-up and then settle down. Flare-ups may occur a few times a month, but the frequency of flare-ups and the severity of symptoms vary from person to person. Mild cases of eczema may cause a few patches of inflamed skin which settle down fairly quickly. More severe cases of eczema, by contrast, can cause widespread inflammation of the skin that lasts several weeks.
Symptoms of eczema in children often improve as they get older.
The exact cause of atopic eczema is unknown. There are number of factors that may contribute to the development of the condition. Studies point towards a problem with the barrier function of the outer layer of skin. The outermost layer of skin (stratum corneum) prevents too much water from evaporating out of the skin and therefore helps the skin retain moisture. Problems with the structure of this skin barrier can cause the skin to become dry and allow allergens to penetrate the skin.
Recent studies suggest that the problems with the skin barrier result from reduced production of a structural protein called fillagrin. Atopic eczema has also been associated with defects in the gene that encodes fillagrin.
In addition to the fillagrin gene, there are likely to be other genes involved in the development of the condition. When two parents have eczema, there is an 80% chance their child will also have eczema. When one parent has eczema, there is a 60% chance their child will have eczema. This suggests that inherited genes play a large role in the development of eczema.
There are several things which can trigger a flare-up of eczema, including:
- Irritants – such as soaps and detergents (e.g. washing up liquid)
- Skin infections – particularly infections caused by the Staphlyococcus aureus bacterium
- Inhaled allergens – this is a term for substances that can cause an allergic reaction when breathed into the lungs. They include house dust mites, animal hair and pollen.
- Contact allergens – this is the term for materials that can cause an allergic reaction when in direct contact with the skin. They include certain metals such a nickel or gold and certain ingredients in topically applied medications.
- Food allergies – allergies to certain foodstuffs e.g. cow’s milk, peanuts, soya, wheat or egg, can trigger atopic eczema.
- Cold or hot temperature – eczema is typically worse in winter and better in summer, but sweating from warm weather can also make eczema worse. Extremes of temperature may trigger flare-ups.
- Hormonal changes – symptoms of eczema may get worse in women during the days before a period or during pregnancy.
A GP may diagnose eczema based on a simple examination of the skin. Further investigations are not usually required. Your GP may want to ask questions about any triggers and whether you or your family have a history of asthma, hayfever or other allergies.
You may be instructed to keep a food diary in order to ascertain whether a particular food is causing an allergic reaction and worsening the symptoms of eczema.
Referral to a specialist
Your GP may want to refer you to see a dermatologist if current treatment for eczema is not working. You may also be referred to a dermatologist if you suffer from recurrent infections of the skin. In the event your GP suspects a food allergy, you may be require further testing by an immunologist or dermatologist.
Atopic eczema cannot be cured, but there are various treatments which can help to reduce symptoms.
There are two main types of treatment for atopic eczema:
- Emollients or Moisturisers
- Topical corticosteroids
A GP may sometimes combine these treatments.
Emollients moisturise dry skin, which in turn can reduce inflammation and reduce the frequency of flare-ups. Emollients include ointments, creams, lotions and bath/shower additives.
Ointments contain less water and more oil and, as such, are greasier than creams and lotions. They are generally better than creams and lotions at keeping the skin hydrated, but can be messy to use. Ointments may be a better option for very dry skin. Lotions contain the least amount of oil, and are the least effective at helping the skin keep its moisture. They are best used on hairy areas of skin such as the scalp.
Emollients should be applied to the skin regularly, often several times a day. They should be used even when you are not experiencing a flare-up, as they prevent the skin from becoming dry and further inflamed.
Topical corticosteroids are creams and ointments that contain steroid drugs such as hydrocortisone or betametasone. They work by reducing inflammation and are used to treat flare-ups of atopic eczema.
For mild flare-ups, a mild topical corticosteroid such as 1% hydrocortisone is prescribed. For more severe flare-ups, a more potent steroid such as betametasone valerate or clobetasone butyrate is used. Topical corticosteroids are applied to the skin during a flare-up and should be continued typically for 48 hours after symptoms have reduced.
They may cause a slight stinging sensation when applied to the skin. Long-term use of topical corticosteroids can cause thinning of the skin. In general, they should be applied for a maximum of 5 days.
Topical calcineurin inhibitors
Topical calcineurin inhibitors include drugs such as tacrolimus and pimecrolimus. They work by suppressing the immune system and reducing inflammation of the skin.
Studies have shown topical calcineurin inhibitors to be effective in treating atopic eczema, but they are generally reserved as a second-line treatment i.e. only after emollients and topical corticosteroids have been tried.
Anti-histamine medications are used to combat itching in eczema. They work by blocking the effect of a substance called histamine, which is released during an allergic reaction. They are sometimes prescribed for severe itching.
Anti-histamines can make you drowsy, although this may be preferable if itching is interrupting your sleep. There are also ‘non-sedating antihistamines’ available, which do not make you drowsy.
Bandages and wet wraps
Covering the skin in medicated bandages or wet wraps can help soothe the skin, help it retain moisture and prevent you from scratching the skin. Bandages and wet wraps can be applied over topical corticosteroids and emollients.
In very severe cases of atopic eczema, steroids may need to be taken orally. The drug prednisolone may be prescribed for a short while. Long-term use of oral steroids is discouraged as it can cause side effects such as thinning of the skin and bruising.
Oral and topical antibiotics
Antibiotics are drugs that fight bacterial infections. You may need to take them if your skin is showing signs of infection. For isolated patches of infected eczema, topical antibiotics (creams or ointments containing antibiotics) may be prescribed.
In very severe cases of eczema, a dermatologist may consider using immunosuppressant drugs to reduce inflammation of the skin. These drugs include azathioprine, ciclosporin and methotrexate. They have the potential to cause severe side-effects e.g. liver damage and so regular tests are needed to monitor your health while taking these drugs.
Phototherapy involves exposing the skin to ultraviolet (UV) light using a special lamp. The ultraviolet light helps to reduce inflammation of the skin. Dermatologists sometimes use phototherapy as a treatment for atopic eczema. Depending on resources, you will probably have to go to a hospital dermatology department to receive this treatment.
There are two types of phototherapy:
- Narrow Band Ultraviolet B (UVB) phototherapy
- Psoralen and Ultraviolet A (PUVA) phototherapy
In PUVA (Psoralen and Ultraviolet A), people with eczema take a medication called psoralen, before being exposed to the UV light. Psoralen sensitises the skin for treatment with UV light. It can be taken orally or applied to the skin as a cream or by soaking in a bath.
Long-term treatment with PUVA is not recommended as it increases the risk of skin cancer. It may also cause itchiness, nausea and a burning sensation in the skin.
There are several lifestyle measures that can help control the symptoms of eczema.
Avoid scratching – scratching can further damage the skin and increases the risk of bleeding and infection. By damaging the skin barrier, scratching leads to a greater loss of moisture and the worsening of dry skin. Repeated scratching over long periods of time may also cause the skin to thicken. In order to avoid scratching, you may find it helpful to:
- Keep your nails short
- Keep the skin covered with clothing
Try gently rubbing your skin (rather than scratching) to ease itching
Avoid known triggers – contact with certain clothing fabrics, using certain cosmetic products, extremes of temperature etc. may cause flare-ups of eczema. If possible, try to avoid the things which you know trigger your eczema. For example, it may be helpful to avoid wearing woollen clothing, which can irritate the skin, and opt for smooth, cotton clothing instead. Similarly, some people find it helpful to avoid biological detergents and fabric conditioners when washing their clothes.
Although house dust mites can cause allergic reactions, there is limited evidence that deep cleaning of your house can reduce house dust mite numbers adequately to reduce the symptoms of eczema. Similarly, unless you have a specific allergy to a foodstuff, there is no evidence to show that avoiding certain foods such as eggs or dairy can have a beneficial effect in eczema.
Use a soap substitute when washing – normal soaps and bubble baths can dry out the skin and worsen the symptoms of eczema. Aim to use soap substitutes and/or a bath/shower emollient instead.
Apply emollients regularly – it is important to apply emollients regularly, rather than wait until the skin becomes dry. This ensures the skin is kept well moisturised and reduces flare-ups.
Ashcroft, D. M., Chen, L. C., Garside, R., Stein, K., & Williams, H. C. (2007). Topical pimecrolimus for eczema. The Cochrane Library.
Atopic Eczema. NHS Choices. Available online at: http://www.nhs.uk/Conditions/eczema-(atopic)
Atopic Eczema. Patient.info. Available online at: http://patient.info/health/atopic-eczema
Atopic Dermatitis and Eczema. Patient.info – Professional Reference article. Available online at: http://patient.info/doctor/atopic-dermatitis-and-eczema
NICE CKS: Eczema – atopic (July 2015). Available online at: http://cks.nice.org.uk/eczema-atopic