Eczema is a long-term skin condition that causes itchy, inflamed, swollen and crusty patches of skin. About 20% of children in schools nowadays suffer from eczema, and incidence is rising in adults too. It can be worsened by environmental triggers, like food or items in contact with the skin, but it also has an immune component. The underlying changes in the body are very similar with eczema, asthma and hay fever. All are due to allergic reactions where the immune system reacts to normally harmless substances. They are all classed as ‘type 1 hypersensitivity’.

How does it work?

Our immune system has millions of antibodies and each one recognises a specific invader. In people with allergies, antibodies called IgE are formed when someone is exposed to a ‘harmless’ invader or allergen such as pollen, cat or dog saliva, feathers, cow’s milk, eggs, shellfish, etc. These antibodies attach to mast cells which are present in large numbers in the mucous lining of the respiratory and digestive tracts and in skin tissue. On re-exposure to the allergen, the IgE antibody grabs hold of it and tells the mast cell to release chemicals, which provoke an allergic response. 

You may have heard of the main chemical that causes inflammation – histamine. This is why ‘anti-histamines’ are given to dampen down allergic inflammation, such as with hay fever or itchy eczema. Inflammation is normally a good thing if you are fighting a harmful invader, but in the case of eczema, asthma and hay fever, it is an over-reaction to a harmless substance. Inflammation means that blood capillaries widen allowing more blood to flow to the area, bringing more antibodies to fight the invader. The increased blood flow causes redness and warmth. Water also seeps from the capillaries in an attempt to dilute any poisons that may be at the site – this causes swelling. If the mast cells ‘switched on’ by the IgE antibodies are located in the mucous lining of the nose, they also cause the production of excessive mucous and so a runny nose is the result. If the mast cells are in the lining of the lungs, the histamine and other chemicals also cause contraction of the airways and mucous production in the airways, leading to blockage, or asthma. If the allergic response happens in the skin, then it’s labelled eczema.

Is it genetic?

The tendency is for all three conditions to run in families, and yet if an identical twin has eczema, in one-in-five cases the other twin will not develop symptoms. This is because all allergies have triggers that differ from person to person. You can potentially switch some of these hereditary triggers off through improving gut health and eating a more plant-focused diet.

What causes eczema flares?

Irritants like soap, detergent and bubble bath as well as cold or dry weather can be triggers. As for causes, I suspect the gut microbiome plays an enormous role as to which allergies occur, and also helps to dictate which genes are switched on and off in each individual. The acid mantle of our epidermis that develops at birth has an important barrier function, as well as maintaining a microbiome environment on the skin to prevent eczema. This can be affected in kids who have been delivered by Caesarean section, antibiotics, breast-feeding and diet. In adults, diet, hormones, environmental triggers and stress can all play a part.

In children, one of the main triggers is food – cow’s milk, eggs and nuts are the top three contributors. Others in the top seven are house dust mites, fish, soya and wheat. It’s also worth being aware that if a child has eczema and a nut allergy, they are 80 per cent more likely to develop asthma later in childhood. Adults with eczema may be more likely to react to birch pollen-associated foods like apple, carrot, celery, and hazelnut.

Another trigger is infection – infected areas of already vulnerable or broken skin are a big component of eczema. Many people with eczema are nasal carriers of a bacteria called staphylococcus aureus. All they have to do is rub their nose or sneeze and then scratch their skin and they can develop a secondary infection overnight. Staph aureus also reduces the amount of steroid receptors on the skin, which means steroid creams have to be stronger to have an effect. If you a prone to infected eczema, the good news is dealing with infections early using a nasal antibiotic, and swabbing the nose if necessary, can be useful in getting things under control.

The third trigger for flare-ups is stress. This can occur with myriad life circumstances including viral infections and teething in younger children, to moving years in school, bullying, or exams in older children. These can all lead to flares, so its worth being aware beforehand to minimise the impact and increase the mositurising regime. Breathing techniques, mindfulness, meditation, exercise, building social networks, me-time and many other self-care practices can help with this. Being aware of stress as a trigger can encourage you to look for solutions that are not just focused on the skin.

How do doctors treat eczema?

Moisturisers are an important component of treatment, providing relief of itching and pain. We have to get good at giving moisturisers to kids with eczema, which is an important component of treatment. Remembering to moisturise before school or work, when you get home and at bed-time too. In babies and children, limiting bathing to 5-10 mins in luke-warm water is helpful too, not longer. Oat based treatments can be useful (and some find relief when putting oats in the bath using a pair of tights to filter the oats through the water!).

Epsom salts in bath water can also be incredibly helpful for eczema. Epsom Salts are made from magnesium and sulfate, which have an anti-inflammatory and anti-itch effect. Because magnesium sulfate is hydroscopic, i.e. draws water to itself, it often acts as an antimicrobial and prevents the overgrowth of bacterial and fungal elements directly on the surface of the skin. When you have eczema, the skin barrier function can be compromised, but Epsom salts can refresh and strengthen this skin barrier, allowing the beneficial microbial flora on the skin’s surface to flourish.

Steroids are prescribed by doctors for flare ups, and moisturisers are more for prevention and maintenance.  When a steroid cream is prescribed, people are naturally worried about side effects. Steroids work to reduce inflammation to the top layer of skin. Fortunately, it takes about six weeks to get any evidence of skin thinning with application of a daily steroid cream on the skin, so if it’s necessary there’s no need to partially treat for a few days – better to use for the full week, or up to 2-3 weeks if necessary. Do not over-use steroid creams though - if steroid creams are used continuously for prolonged periods, a withdrawal reaction can occur on stopping treatment. This can cause redness of the skin which can extend beyond the initial area treated, a burning or stinging sensation, intense itching, peeling of the skin, and sometimes open sores.

Severe cases of eczema will be seen by a dermatologist for other treatments targeting the immune system, and they may also use light therapies. Skincare routines that include antioxidants (vitamins A, C and E) and SPF are usually suggested by skin experts too. I always like to emphasise lifestyle changes and diet changes that can help to improve eczema from the inside out.

Diet and eczema

It’s known that some foods trigger allergies, while others protect us. The most common foods linked to eczema are cow’s milk (the number one culprit!) and eggs. Lesser triggers are fish, soya, wheat and nuts, according to the National Eczema Society.

Remember how eczema, asthma and hay fever are all related to each other? Some foods help protect against allergies more generally. For example, research has shown that people who ate the most fruit and vegetables had the healthiest lung function. Vitamin C (from fresh fruit and vegetables) and E (from nuts and seeds, avocados, tomatoes, wholegrains etc) are also believed to help reduce the severity of the inflammatory response in the lungs of people with asthma.

Another example of how diet affects allergies studies that have shown that if a breastfeeding mum’s diet is high in animal fats and low in omega-3, the risk of her baby developing allergic conditions increases. Trials have shown that rubbing omega 3 rich oils on children with eczema helps alleviate the condition; as does consuming diets rich in omega 3s. These are the good fats found in oils from flaxseed, rapeseed and soya as well as nuts (esp. walnuts) and leafy green veg. These fats are incorporated into the skin cell membranes and so help lock in moisture. If you are aiming to limit fish for reducing toxin load, or for specific allergy reasons I would strongly recommend a long chain omega 3 fatty acid supplement such as EPA/DHA from algae oil. These can be bought in capsules, or in liquid form for young children.

Limiting or avoiding processed foods has also shown to be of benefit in many children with eczema. The Korean National Health and Nutrition examination of over 17,000 people found that those whose diets contained the highest amounts of meats and processed foods had a 57 per cent greater risk for atopic dermatitis (eczema) when compared with individuals whose diets contained the least. Additionally, the International Study on Asthma and Allergy in Children (ISAAC) performed in Colombia found that children whose diets contained the highest amounts of traditionally eaten foods, such as fresh fruit and legumes, had an almost 40 per cent lower risk for having eczema, compared to those eating the lowest amounts of these foods.

What about histamines in foods – should they be avoided?

Yes and no. In general, any fermented/aged foods or foods containing a lot of certain bacteria have high histamine. Fermented dairy (blue cheese, yogurt, buttermilk, kefir), fermented/aged drinks (wine), and aged meats (bacon, sausages, cured ham, etc.) are a few main triggers you should try to avoid. Some citrus fruits and berries also contain high levels of histamine, but are healthy for other reasons so worth keeping in your diet once the gut is in good condition.

As mentioned in my gut health blog, a healthy gut helps to keep the skin healthy too. Improving the integrity of the gut lining will mean many potential food intolerances will diminish. Some bacteria in our guts can actually make histamines without their presence in foods, so getting gut health back on track is key to good skin. Healing the gut can occur with cutting back on processed meats, dairy, and sugars and instead focusing on vegetables, berries and beans, nuts (if not allergic) and seeds. Beans, peas, nuts, seeds and soy all contain B6 – this is an important vitamin to help the enzyme that breaks down histamine and lines our gut (DAO) to work properly. As mentioned, having omega 3 fatty acids and a mainly whole food plant-based diet will be very helpful. If you decide to eat a fully whole-foods plant-based diet, that’s wonderful. If so, B12 supplementation will be essential. It is available in a number of forms, including an oral spray, tablets or in fortified foods such as cereals, plant milks and marmite. Vitamin D is also important for gut and skin health. Keeping useful bacteria alive by avoiding unnecessary antibiotics and eating plenty of vegetables will help too.

Bottom line?

Allergies are now so common in the UK that the Royal College of Physicians is referring to them as an epidemic of the skin. Although there is a strong genetic component involved, it is essential to boost your health and improve the functioning of your immune system to minimise the chances of a flare-up. This means:

• Eat a healthy diet rich in fruit, vegetables, nuts, seeds, wholegrains and omega-3s.
• Exercising regularly helps keep the heart, bones and digestive system healthy and helps to keep a healthy weight.
• Find ways to make yourself feel good and better able to cope with the stresses of everyday life too.

References

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