Eczema: Q and A
Q. What is eczema?
A. Eczema (also known as atopic dermatitis) is an itchy inflammation of the skin, often found in association with dry skin.
Eczema most often first appears in babies younger than 12 months, but can start at any age. Eczema often gets better as you get older, but problems with dry, sensitive skin often persist.
Q. What are the symptoms of eczema?
A. Eczema is an itchy, scaly red or pink rash. The skin may be dry and flaky, and sometimes the eczema rash is accompanied by oozing and crusting. Over time, itching and scratching can lead to thickening and cracks in the skin.
The rash of eczema can occur anywhere on the body. In babies it often occurs on the face, especially the cheeks and chin. In older children, it commonly affects the insides of the elbows, behind the knees, the wrists, ankles, neck and hands. In adults, eczema often affects the neck, upper body, wrists and hands, and the skin around the eyes.
Q. What causes eczema?
A. The exact cause of eczema is not known, but it is thought to be due to a combination of genetic and environmental factors.
Eczema often occurs along with allergies and people who have eczema are more likely to also develop allergic rhinitis (hay fever), asthma or other types of allergy-related (atopic) diseases. Many people with eczema have family members with eczema, asthma and hay fever.
Q. What genetic factors contribute to eczema?
A. Researchers have discovered that nearly half of eczema sufferers studied have mutations in the gene that makes a skin protein called filaggrin. Filaggrin is found in the outer layers of normal skin and plays an important role in the skin’s ability to form a barrier to keep moisture in and foreign substances out.
When the body can’t make filaggrin properly, the skin dries out too easily and can crack and become ‘leaky’. This deficient skin barrier allows allergens (substances that cause allergies) and irritants to get in. This increased penetration of allergens (e.g. dust mites, pollen) and irritants (e.g. soaps, solvents), through the skin’s barrier is thought to stimulate the immune system, triggering the skin to release chemicals that cause itching.
This process is believed to prime the immune system, leading to an exaggerated response in the skin of people with eczema, and possibly even leading to hay fever, asthma or food allergies.
This idea that the skin barrier defect is the primary problem, which then subsequently leads to the immunological overreaction in eczema, is a turnaround from the previous accepted scientific wisdom that eczema resulted from an immune problem in the body.
While not everyone with eczema has a mutation in the filaggrin gene, there may be gene mutations for other structural components of the skin that are important in eczema, and the filaggrin finding highlights the importance of trying to keep the skin barrier intact by using moisturisers.
Researchers are investigating whether restoring the skin’s barrier early in life in people with filaggrin mutations can prevent the sensitisation and subsequent development of eczema and some other allergic diseases.
Q. What can trigger eczema?
A. Eczema can be triggered or worsened by a number of factors including allergens and irritants. The following can be eczema triggers.
- house dust mite antigen
- animal fur or dander (fine skin or scales)
- chlorine in swimming pools and spas
- soap, bubble baths, shampoos and detergents
- perfumed creams and ointments
- certain materials and fabrics, for example wool
- dryness of the skin, which can be exacerbated by air conditioning and indoor heating
Temperature and humidity
- changes in the temperature – being too hot or too cold
- extremes in humidity – hot and humid or cold and dry weather
- getting hot and sweating
- dry, over-heated rooms
- in most people, food doesn't cause or aggravate eczema
- food allergy is rarely a trigger for eczema. Some people with eczema do also have food allergies, but these are often unrelated to their eczema
- most food allergies that aggravate eczema go away within the first few years of life
- Stress and feelings such as anger and frustration can contribute to eczema flare-ups.
- Eczema affecting the hands may develop in people with jobs that involve frequent hand washing or exposure to chemicals or grease (such as jobs in health care or food preparation).
Q. Are there any tests used to diagnose eczema?
A. Doctors can usually diagnose eczema based on the appearance of the skin and the history of symptoms.
If your eczema is severe and seems to be related to an allergy, your doctor may recommend you have allergy testing, including blood tests.
Skin prick tests can be misleading in people with eczema, because they are done by scratching the skin which can be aggravating in itself and provoke a reaction not necessarily related to the allergen being tested. Allergy testing is usually done by a specialist in allergies.
Q. What can I do to treat my eczema?
A. Treating eczema is a proactive, ongoing process which involves trying to maintain the skin's barrier as much as possible – to keep moisture in, and irritants and allergy triggers out. Self-care measures that can help treat eczema include the following.
Improving skin condition
- Use emollients (moisturisers), such as aqueous cream or sorbolene cream, to keep dry skin hydrated and reduce irritation. Moisturisers should be applied promptly after patting the skin dry after showering or bathing. Sorbolene may cause mild stinging when applied to broken skin. Ointments such as emulsifying ointment are greasier and harder to apply, but good for very dry or scaly areas. Moisturisers need to be applied at least twice daily to improve very dry skin.
- Avoid scratching when possible. Patting or pressing the skin may help, as may applying soothing moisturisers. Applying a cold compress, made by dipping a cotton cloth or a washcloth into ice cold water and squeezing it out, can soothe the itching of eczema and reduce the urge to scratch. Keep your fingernails short to reduce the impact of scratching.
- Coal tar products are available from pharmacies to ease the itch of eczema.
- Oatmeal baths can also help ease severe itching. There are products available that contain colloidal oatmeal or you can try putting half a cup of uncooked oats into a stocking or sock and adding it to the bath water.
Avoiding triggers for eczema
- Avoid skin irritants, such as perfumed soaps, shampoos, washing powders and fabric softeners. Sorbolene cream, Aqueous cream or non-drying skin cleansers can be used as an alternative to soap products. For very dry skin, there are dispersible oils that can be added to bath water or sprayed on to wet skin after showering. There are hypoallergenic products or shampoo substitutes available from pharmacies. Unscented, mild washing powders are available.
- Avoid allergens, such as house dust mite antigen, animal dander (skin and hair), moulds and grass pollens, as much as possible.
- Avoid swimming in chlorinated pools as chlorine can be an irritant to skin.
- Do not bathe more than once per day, and have brief, lukewarm (rather than hot) showers.
- Wear cotton clothes and minimise contact with wool or synthetic materials when possible. Also avoid doonas – use cotton blankets and sheets instead.
- Avoid overheating, especially in bed at night.
- Wear protective gloves when using chemicals or detergents, or when gardening.
Q. What can I do to treat an eczema flare-up?
A. As well as taking the general self-care measures above to manage eczema, there are specific treatments that may help an eczema flare-up (or flare).
- Corticosteroid ointments and creams can help reduce inflammation, and should be used daily to treat eczema flares. The type and concentration of steroid will depend on the area of skin that is involved – check with your doctor. Side effects are possible, but generally speaking, the risks of not treating eczema outweigh the risks of corticosteroid side effects. Low concentration corticosteroid ointments or creams, such as hydrocortisone, are available from pharmacies over the counter and can be used to treat exacerbations of eczema. These are safe when used properly. Follow your doctor’s or pharmacist’s instructions on how much to use.
- For eczema where a low concentration cream has not worked, methylprednisolone aceponate (brand name Advantan) or another more potent steroid ointment or cream may be recommended.
- Pimecrolimus (brand name Elidel) is a so-called called calcineurin inhibitor – a non-steroid anti-inflammatory cream that can be prescribed by your doctor and is often used for eczema of the face.
- Wet dressings (which involve applying steroid cream and then covering the area with a damp bandage, clothes or towel for 15-60 minutes) can be used to treat flare-ups of moderate to severe eczema. They allow greater penetration of the steroid cream. Wet dressings are generally only needed for a few days at a time.
- Another technique that can be used instead of wet dressings is known as the soak and smear technique. This involves soaking in a warm bath for about 20 minutes before bedtime at night, and applying corticosteroid to affected skin straight after the bath (do not dry the skin with a towel). You then put on comfortable pyjamas with your skin still damp. In the morning, you should apply moisturiser to your skin.
- Anti-bacterial bath oils can be used. The skin of people with eczema often shows high rates of colonisation by the bacterium Staphylococcus aureus. Reductions in the levels of Staphylococcus aureus can help improve eczema. Take care to follow the bath oil instructions carefully, as these products may cause irritation if used undiluted.
- Watch for crusting, oozing, pustules, pus or weeping skin which may be a sign of infection. Your doctor may need to prescribe antibiotics if your eczema has become infected.
- Sedating antihistamines taken at night may help if itching is interfering with sleep; however, the itching of eczema is thought not to be due to histamine, so any benefit is due to the sedation, not reduction of itching.
Q. What complications may be associated with eczema?
A. Having broken, scratched or weeping skin caused by eczema can leave it susceptible to a secondary infection. This can be a bacterial infection, such as impetigo, or a viral skin infection, such as cold sores (herpes simplex virus).
Q. How can my doctor help my eczema?
A. Your doctor can confirm that your skin condition is eczema and can help you to identify triggers for your eczema that you should try to avoid.
Your doctor can also help you to formulate a plan to manage your eczema effectively. If required, they can prescribe corticosteroid ointments or creams, and if your eczema has become infected they may prescribe antibiotics. If your eczema does not respond to a management plan then your doctor may refer you to a skin specialist (dermatologist).
A skin specialist may recommend a course of ultraviolet light therapy, or phototherapy, if your eczema recurs frequently. Medicines that suppress the immune system may also be prescribed for people with very severe eczema.
2.BMJ Best Practice (Patient information from BMJ). Eczema (published 1 Dec 2016). http://bestpractice.bmj.com/best-practice/pdf/patient-summaries/532148.pdf (accessed Dec 2016).
3. Australasian Society of Clinical Immunology and Allergy (ASCIA). Eczema (atopic dermatitis) (updated Dec 2013). http://www.allergy.org.au/patients/skin-allergy/eczema (accessed Dec 2016).