Busting eczema myths

Eczema is a chronic inflammatory disorder of the skin that affects at least 15 per cent (up to 20 per cent) of children here, and often rears its head in the first few months of life.

In 95 per cent of cases, eczema (also called dermatitis) manifests itself in the first five years of life, and its presence can be the first indicator of a slew of other conditions like asthma and rhinitis to follow - a phenomenon otherwise known as atopic or allergic march.

According to the World Allergy Organisa-tion (worldallergy.org), atopic march refers to the natural history of atopic manifestations, which is characterised by a typical se­quence of antibody responses (levels of immunoglobulin E or IgE) and clinical symptoms that appear early in life, persist over years or decades, but usually fade spontaneously with age.

Eczema receives a fair amount of media coverage, yet it is still shrouded by a cloud of myths, such as one where certain food is blamed as the cause of the condition, or that there is the existence of a magical cream out there that can make it go away once and for all.

Recent results from birth cohort studies have uncovered new information regarding genetic and environmental factors that promote the development of eczema.

These results now allow skin specialists such as Dr Leong Kin Fon to tell parents that they are usually wrong if their first reaction is to blame food when their child displays symptoms of atopic eczema.

"In many cases, food allergies is usually not the causal agent," contends the paedriatic dermatologist at the Kuala Lumpur General Hospital.

"Some parents substitute cow's milk with goat's milk, and then with soy-based milk, but still could not get satisfactory results.

They start to get frustrated, and begin to think it is all due to food," the physician told journalists during an eczema media workshop recently organised by Stiefel, a company that specialises in making skincare products, now owned by GlaxoSmithKline.

That people readily blame food or food allergies as the cause for itchy skin or eczema is not surprising, considering that there is a high degree of correlation between those with eczema and those with other allergies.

"Food allergies can coexist in someone with eczema, but that is not the same as saying that food is the cause of eczema," said Dr Leong, who added that it is only in 5 per cent of cases of eczema in children under five-years-old where food allergy co-exists as a triggering factor, but even then, they still cannot be called a causal factor.

Itch-scratch cycle

Eczema is characterised by dry, flaky skin, and those who suffer from it have to bear with going through countless rounds of the itch-scratch cycle.

Having uncontrolled eczema is akin to being "pricked by 1,000 mosquitoes at the same time, and not knowing where to start to scratch".

"Not only does it cause intense discomfort, but sufferers also have to endure a huge psychosocial impact, such as reluctance of being seen in public, as they would have red, inflamed skin, flaky skin, and so on.

In the case of toddlers, they would just wriggle continuously in bed to get some relief, and often, even the parents' sleep is disrupted as a result," said Dr Leong.

Scratching damages the skin, and allows penetration and colonisation of bacteria on the stratum corneum, or outer, layer of the skin.

This leaves patients more at risk of dry and brittle skin, which becomes sensitive to chemical impact, and entry of irritants and allergens.

The secretions of bacteria and other microbes can further add to the pain by causing further swelling, intense itching, and infection.

Over time, the skin becomes scaly and crusty.

Skin dryness is also a common feature in those with eczema, and dry skin and itch is a fiery combination as it encourages scratching.

Various theories have been formulated to explain why some people's skin are more prone to losing their ability to hold water or moisture, making them more prone to eczema.

A recent explanation, called the Epidermal Barrier Dysfunction theory, posits that changes in at least three groups of genes encoding structural proteins, epidermal proteases and protease inhibitors combine to create a defective epidermal barrier, which in turn increases the risk of developing eczema.

The outer part of the skin forms a barrier against diffusion of water, and also acts as a barrier for microbes and chemicals.

This stratum corneum layer contains much water, and is supple and flexible in the healthy state, but becomes brittle when dehydrated. The more "perfect" the skin protective coat, the higher the water content will be, while keeping any transepidermal water loss (TEWL) low.

A marathon, not a sprint

The converse happens in skin with a dysfunctional or abnormal epidermal barrier, where it loses more water (high TEWL).

It has been suggested that epidermal barrier dysfunction that leads to high TEWL is a chief event in the development of eczema. Regardless of how the theory pans out, there is definitely a place for the use of moisturisers to replenish the skin or to minimise TEWL.

Not many people are aware that managing eczema is a marathon, and not a sprint.

"A lot of parents get upset that their child's condition is not cured the next day or week when they bring their child to see a skin specialist. They are constantly on the lookout for that magic pill or cream that will provide a cure once and for all," said Dr Leong, who added that the disease also has a genetic dimension to it.

"If a parent has it, chances are high that the couple's child will also have it. The odds become even higher when both parents have it."

While treatment of the condition may prove to be challenging for many, eczema can be successfully managed with the right medical advice, and there is medication that can provide relief for itchiness so that the itch-scratch cycle can be broken.

Topical steroids have a valuable role in the management of eczema, though Dr Leong recognises that there is a group of parents who are "steroid-phobic".

"At the other end of the spectrum, there are those who are ever so ready to procure the latest of the most powerful steroids. This so-called steroid-dependant group are typified by those who would probably head to the pharmacy to purchase steroids after the third visit to doctor," observed Dr Leong.

There are inherent dangers in self-medication with steroids as some pharmacists don't even ask whether the steroid is for an adult or a child, or enquire whether the application is for the face or hand. The tendency is for the consumer to get something that is very "strong".

And the parents can be amazed at the initial results. But two weeks later, they go back to the doctor again as the improvement cannot be sustained.

Caution against super-strong steroids

In the long run, management of eczema cannot just be limited to using steroids, and Dr Leong cautions that super-strong steroids can lead to skin-thinning, rendering the skin vulnerable to further environmental and biological assaults.

"It is also possible to eventually wean a person off steroids, but for those with moderate or severe eczema, there is a right time and right place for steroids. We use them not because we have no choice, but because they work.

However, people should not self-medicate using steroids," cautioned Dr Leong.

However, there is no reason for someone to avoid outdoor activities or exercise just because of eczema.

As sweating cannot be avoided in the tropics, frequent short showers can help to prevent the build-up of stale sweat, which can act as a trigger for flare-ups.

That said, soaps or cleansers that are overly harsh on the skin (hypoallergenic products may be necessary for some) should be avoided.

Long soaks in the hot tub should also be avoided as soaking the skin for a long time will actually lead to water loss (like "pruning" seen in the fingers when one swims for too long).

Finally, there are environmental factors that need to be taken into account, such as the presence of dust mites in the home.

"Dust mites are not so much a problem in temperate countries, but they are an important factor here due to the temperature and humidity," noted Dr Leong.

As far as atopic eczema management is concerned, Dr Leong is skeptical about the value of pinprick tests or blood tests (for serum IgE) to determine what one is allergic to.

"Thinking that their condition is caused by one single cause or allergen, some people spend thousands of dollars going to diagnostic laboratories to find out what they are allergic to.

The premise behind such allergy tests is to identify the allergen(s) so that they can be eliminated.

Light at the end of the tunnel

Sometimes, allergy testing can be misleading because someone may have an allergic reaction to a food that is not responsible for the eczema flare-up," said Dr Leong.

Atopic eczema is not like the usual occupationally-derived eczema, whereby a susceptible individual comes into contact with a specific allergen such as nickel, a particular detergent, or something else, in the course of work. The latter is much easier to manage as it involves only a single agent - remove the agent, and the condition goes away.

For those who are inclined to think that the problem will be solved just by going for allergy testing, Dr Leong cautions that life is often not as simple as that. "Even if you know that dust mites are the allergen, you can only partially reduce the dust mite population, but you can never get it down to zero. And if sweat is the allergen, how is it possible for one not to sweat? You can only minimise it."

For Dr Leong, the greatest mistake one can make is to believe that there is a magic pill, or an expert doctor that can heal them once and for all. "People go from Western to traditional Chinese medicine to a host of alternative approaches, especially if the first doctor did not do a good job of explaining things. Or sometimes people self-medicate, or follow the latest herbal fad, before ending up with some organic probiotics and so on, but still could not find a long-term solution.

"As eczema is multifactorial, managing eczema needs a combination approach. You cannot rely on one single cream or moisturiser to manage it for the next five to 10 years. And even if you have no problems with steroids, at the end of the day, please don't overwork your steroids as it needs to be supported by things like lifestyle changes and environmental modifications."

If you are in your early teens or early childhood, the good news is that 70% of people will eventually "outgrow" their condition.

"Always remember that the majority will be able to manage it to a very satisfactory state. There is definitely light at the end of the tunnel, and even though we cannot cure you, we can still walk with you."

References:

1. www.worldallergy.org/professional/allergic_diseases_center/allergic_march/

2. www.ncbi.nlm.nih.gov/pmc/articles/PMC2957505/?tool=pmcentrez

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