Eczema is the result of a disruption in the barrier function of the skin. If one was to think of the skin as a brick wall between the body and the external environment, we can compare the skin cells to the bricks of the wall and recognise that to form a good defence we need important supporting structures and a layer of plaster there over. In eczema, these important structural elements are missing or ineffective and the skin is missing the nice oily layer which functions like plaster- keeping the moisture inside the skin and allergens and infections out. Thus, people with eczema have skin that becomes dry very easily and are vulnerable to irritants and allergens in the environment because they do not have a good defensive barrier. This results in an inflamed and itchy skin which leads to scratching and further destruction of the barrier function.
The most important part of treating skin with eczema is to apply emollients. These are moisturisers, with varying amounts of oil-in-water combinations, that help hydrate the skin whilst simultaneously replacing the oily layer, restoring the barrier function of the skin.
What about steroid creams?
Topical corticosteroids are important anti-inflammatories that are applied directly to the skin. They are used in many skin conditions, including eczema. In eczema inflammation of the skin results in redness, swelling and itching. Topical corticosteroids work at the cellular level to reduce the production of pro-inflammatory messages, thus helping the skin to return to a cool and calm, healthy state. They are needed when areas of the skin experience flares, which may occur frequently or infrequently depending on the severity of the eczema.
There are many different topical steroids available. They vary in terms of strength (potency) and vehicle (ointment, cream or lotion). Your doctor will prescribe different topical steroids based on the severity of the eczema and the part of the body affected. For example, the skin on the face is thinner and more sensitive so one has to be careful about using too potent a steroid. The skin on the scalp is covered by hair so a lotion is preferable as a cream/ointment won’t be able to penetrate the hair to reach the skin.
What about the side effects?
Using a topical steroid that is too potent for too long may result in thinning of the skin, discolouration and dilatation of the blood vessels. The skin may become more fragile and bruise or lacerate more easily. More rarely topical steroid use may lead to contact allergy- with a worsening of skin symptoms- either due to constituents of the preparation or to the steroid molecule itself. Prolonged use of potent topical steroids may produce rebound symptoms upon withdrawal, which may range from increased redness and itching to the ’Red burning skin syndrome’ in which the majority of the skin is red and burning.
However, it must be noted that appropriate use of the correct topical steroid will result in resolution of eczema symptoms in the vast majority of people, without adverse effect. Always seek guidance from a medical professional to prevent overuse. Untreated eczema in itself is damaging to the skin causing thickening, discolouration, scarring and vulnerability to infection. A pro-active approach, in which topical steroids are used intermittently, may greatly reduce exacerbations in flare-prone individuals and result in less topical steroid use overall.
Are there any alternatives?
As mentioned previously; meticulous attention to the use of moisturisers, in conjunction with good general skin care, is the cornerstone of eczema management. Individuals with mild eczema or those in flare-free intervals may be able to manage their eczema without any anti-inflammatory treatment. Topical calcineurin inhibitors are non-steroid anti-inflammatory therapies that may be used for treatment of eczema. They are not associated with the same adverse effects on the skin but some individuals find they cause a transient ‘burning’ that reduces over time. It must also be noted that they are less effective than some topical steroids and it thus may take longer to clear a flare.
Topical corticosteroids are thus effective, commonly used treatments for those with eczema. They can bring rapid relief of troublesome symptoms and restore the skin to an inflammation-free state. However, overuse or inappropriate choice of the type of steroid use may be associated with side effects. They should thus only be used under the supervision of a medical practitioner.