Eczema is on the increase and there’s no cure. It can have a debilitating effect on your child’s quality of life, as well as yours as a parent. Here’s what you need to know.
A friend of mine once described her eczema as having unbelievably itchy skin which comes from her skin being hot. Her skin gets so hot that she said the only thing that makes it better (even temporarily) is scratching it. She remembers her hands being wrapped in cloth as a small child to stop her from getting at her skin to scratch it at night. Her description of eczema is not unique; talking to other people, and parents of children with eczema, the itch is what is mentioned most often. So why does some people’s skin get so itchy?
the itch
The Greek meaning of eczema is pretty spot on, as it means, literally, “to boil over”. Eczema can occur on any part of the body, and the itch quite often appears before the redness.
According to Dr Gil Yosipovitch, a dermatologist at Wake Forest University and founder/former president of the International Society for the Study of Itch (www.itchforum.org), the chronic itch of eczema lies within how nerve fibres transmit their signals. He describes how there are C-nerve fibres in chronic eczema that may not be functioning in the way they do in people without eczema. These nerve fibres become overactive, so that the scratching intensifies the perception of itch, causing you to itch more and setting up the itch/scratch cycle.
Dr Yosipovitch also describes his theory that circadian rhythms (the body’s master clock) could play a role in the itch/scratch cycle. He says that during the night, certain chemicals, called mediators, are involved in activating itch nerve fibres. Data shows that some of these mediators increase at night. Dr Yosipovitch also raises the point that skin temperature increases at night, and with that increase often comes an aggravated itch.
who can develop eczema?
Anyone can develop eczema, and most eczema develops in childhood, but eczema can also develop in adulthood. Between 15–20% of New Zealand children have eczema. The burden of eczema is disproportionately high in Maori and Pacific children and adolescents. Worldwide, eczema has been shown to be on the increase. And eczema can run in families with a history of other allergies or asthma.
what is the difference between eczema and atopic dermatitis?
“Eczema” is the term used to describe a group of conditions that cause the skin to become inflamed or irritated. The most common type of eczema is known as atopic dermatitis, or atopic eczema. “Atopic” means that the person has a predisposition toward developing certain allergic hypersensitivity reactions. Often when atopic dermatitis is described, so too is the phenomenon “atopic march” or “allergic march” – and this where the child with eczema goes on to develop other allergic reactions such a food allergies, a stuffy, runny nose (rhinitis), or asthma. However, this pattern does not apply to every child, and it is hard to predict how one child with allergy will experience this progression compared to another. Many children who do experience allergic disease in the pattern of an atopic march may grow out of their allergies in early adulthood. Researchers are focusing on understanding more about the atopic march in order to develop treatment to manage it, hoping to ultimately prevent it from occurring in the first place.
what causes eczema?
The exact cause of eczema is unknown, but it’s thought to be linked to an overactive response by the body’s immune system to an irritant. It is this response that causes the symptoms of eczema.
The causes for eczema are varied, ranging from the skin being in contact with rough materials to different soaps or animals. For some people, respiratory infections or a cold can also trigger an eczema flare-up.
Atopic dermatitis is often described as being a disease of altered skin barrier and immune dysregulation. The skin usually offers a physical barrier to the environment, but in people with eczema, there is strong evidence to show that the skin’s barrier abilities are less robust than in a person without eczema. In addition, people with eczema may have components of their immune system not recognising its own cells and tissues, known as autoimmunity.
barrier function
An intact, healthy skin barrier is critical in defending against bacteria, irritants (such as soap), or allergens (such as cat hair). Research has shown that some of the genes in people with atopic dermatitis are deficient in making certain proteins that are important in maintaining the structure of skin. Such proteins include filaggrin, but studies have shown that even though children may have genes that are filaggrin-impaired, they can still grow out of eczema.
immune function
Studies have shown that people with atopic dermatitis produce high levels of immune cells causing inflammation of the skin. The inflammation leads to a cascade of events around the skin, which turns the skin from being dry to red and itchy.
which comes first?
It is not known whether it is the body’s immune response that causes problems with the skin’s barrier ability or the other way around, and work is underway to answer this chicken-and-egg scenario, as this could lead to new ways to manage eczema.
treatment
There is currently no cure for eczema. Steroid creams and emollients (moisturising treatments) are the gold standards in managing the symptoms of eczema. These are aimed at keeping the skin soft and supple, preventing it from drying out and starting that itch/scratch cycle. Some people store their moisturisers in the fridge during hot weather.
In terms of new management approaches, there is a lot of research underway looking at how probiotics can help. The idea behind using probiotics is that they could potentially boost your body’s good bacteria and immune system, which may also help prevent the skin infections that are common in children and adults with eczema.
Many people also bathe in oats (using pantyhose to contain the oats is recommended) because oats are said to leave a protective layer on the skin, which helps keep the skin well moisturised and lowers the skin’s pH levels which may help reduce the itch.
could it be psoriasis?
Psoriasis is also an immune-mediated condition and it occurs because the skin cells grow too fast. This rapid growth causes dead skin cells to accumulate on the surface of the skin, resulting in thick patches of red, dry, itchy skin. It is an incurable, long-term (chronic) skin condition which can be seriously debilitating. Like eczema, psoriasis flares up and causes the skin to itch and can be triggered by environmental factors, as well as by the body’s ability to manage it. Psoriasis commonly affects the skin of the elbows, knees, and scalp.
Both eczema and psoriasis involve skin inflammation; however, eczema generally develops in younger children, while psoriasis is most frequently diagnosed between the ages of 15 and 25. Psoriasis does look different to eczema, and confirmation of diagnosis needs to be done by a GP
or skin specialist.
Although there is no cure for psoriasis, researchers frequently stress the importance of a healthy lifestyle. Eating plenty of fruit and vegetables, getting enough sleep and exercise, as well as keeping stress levels low are all helpful in managing psoriasis.
[byline]
Sara Filoche is a mum of two and a scientist who is interested in how people get sick. She has worked in laboratories in the UK and USA looking for new medicines and is now a health researcher at University of Otago in Wellington.
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