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.
Q. What are the symptoms of eczema?
A. The skin may show a scaly red or pink rash which can be accompanied by oozing and crusting. Over time, itching and scratching can lead to thickening and cracks in the skin. The skin may then become secondarily infected by bacteria such as Staphylococcus or viruses such as herpes. The rash of eczema can occur anywhere on the body, but in babies it often occurs on the face, and in older children on the insides of the elbows and behind the knees. 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. Recently, a significant discovery has shed more light on the genetic factors contributing to eczema.
Q. What genetic factors contribute to eczema?
A. Researchers have discovered that nearly half of eczema sufferers studied had 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, bacteria) 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 or asthma.
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 will now investigate 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 my 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 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
- being too hot or too cold;
- extremes in humidity - hot and humid or cold and dry weather;
- getting hot and sweating.
- in most people, food doesn't cause or aggravate eczema;
- food allergy is rarely a trigger for eczema. Some people with eczema do have food allergies too, 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.
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 radio-allergosorbent (RAST) 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.
Q. What can I do to manage my eczema?
A. Managing eczema is a proactive ongoing process which involves trying to maintain the skin's barrier as well as possible, to keep moisture in, and irritants and allergy triggers out. It also involves controlling inflammation and managing eczema flares as they arise.
- Emollients (moisturisers) such as sorbolene cream can be used to keep dry skin hydrated and reduce irritation. They 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 may need to be applied twice daily to improve very dry skin.
- Avoid skin irritants, such as perfumed soaps, washing powders and fabric softeners. Sorbolene cream or non-drying skin cleansers can be used as an alternative to soap products, and there are dispersible oils that can be added to bath water to help the condition of the skin. Unscented, mild washing powders are available.
- Avoid perfumed and strongly scented shampoos and conditioners; there are hypoallergic products or shampoo substitutes available from pharmacies.
- 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 .
- Avoid overheating.
- Avoid doonas; use cotton blankets and sheets instead.
- Avoid scratching when possible. Patting or pressing the skin may help, as may applying soothing moisturisers. Applying a cold compress, made by dipping sterile 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.
- Coal tar products are available from pharmacies to ease the itch of eczema.
- Wear protective gloves when using chemicals or detergents, or when gardening.
- Avoid allergens such as house dust mite antigen, moulds and grass pollens.
- Avoid other common allergens such as animal dander, which can also be an irritant.
- Avoid swimming in chlorinated pools as chlorine can be an irritant to skin.
- Keep your fingernails short to reduce the impact of scratching.
Q. What can I do for an eczema flare?
A. As well as taking the general measures above to manage eczema, there are specific treatments that may help an eczema flare-up.
- Low concentration steroid creams, such as hydrocortisone, are available from pharmacies over the counter and can be used to treat exacerbations of eczema involving the face and flexures. These are safe when used properly.
- For eczema elsewhere on the body, more potent steroid creams are usually recommended.
- For eczema of the face and flexures where a low concentration cream has not worked, methylprednisolone aceponate (Advantan) is often used.
- You should try to use the lowest concentration that effectively manages the flare-up. Be aware that steroid creams are absorbed at different rates from different parts of the body, e.g. the face absorbs much more than the forearm (which is why low-potency steroid creams are used first for eczema of the face).
- Pimecrolimus (brand name Elidel) is 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 wet bandage or towel for 15-60 minutes) several times a day 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.
- Anti-bacterial bath oils, such as QV Flare Up Bath Oil or Oilatum Plus Bath Oil, 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 has been shown to improve eczema. Take care to follow the bath oil instructions carefully, as these products may cause irritation if used undiluted.
- 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.
- 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.
Q. What complications may be associated with my 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 me?
A. Your doctor can make sure that your skin condition is due to eczema and can help you to identify triggers for your eczema that you should try to avoid. They should also be able to help you to formulate a plan to manage your eczema effectively. If required, they can prescribe corticosteroid 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.
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.
Last Reviewed: 28 August 2009
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