All About Eczema (Atopic Dermatitis)
Posted: 20/02/2018
Updated: 08/07/2018
Eczema can come and go, move around the body and when one plaque clears up, another one may develop. This condition can be painful, irritable and make you feel self-conscious about your appearance.
Eczema is a very common allergic skin condition where patches of skin become red, itchy and inflamed. Sad to say that it has been estimated to affect up to 15 million people in the UK and 31.6 million in the US suffer from different stages and types of eczema (1, 2).
Symptoms
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inflamed
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itchy
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redness
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cracked
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scaling
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rough
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blisters
affected areas
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elbows
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hands
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knees
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ankles
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feet
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buttocks
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wrists
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face
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scalp
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neck
Eczema actually refers specifically to a group of conditions characterised by inflammation of the skin. There are several types of skin conditions that produce eczema (3):
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atopic dermatitis
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contact dermatitis
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xerotic eczema
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seborrheic dermatitis
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many others
Among the many types of eczema, the most common is atopic dermatitis which affects up to 20% of children and up to 3% of adults (4).
Eczema usually starts in early childhood but fortunately, most children will improve their condition once they enter adolescence. Only 20% children continue to have problems as adults. With proper treatment, the condition can often be controlled (5).
Pathology
Let’s start with the anatomy of the skin. The skin is made up of three layers – the outer layer called epidermis, the middle layer called dermis and the inner layer called the subcutaneous layer.
Image from Dermatological E45
The epidermis acts as the skin’s barrier to the outside world. It keeps our internal organs and systems safe from the elements and bacteria that may try to invade our bodies.
The skin oils hold together the skin cells creating a nice strong barrier. Patients with eczema, however, have an impaired barrier function meaning that their skin barrier is broken down letting natural moisture out and allowing irritants and allergens in (6).
The exposure of allergens can result in skin sensitisation (production of IgE antibodies) and the development of an allergy (7).
When the skin becomes dried and cracked, this is known as an eczema flare-up. Ultimately, the inflammation makes the skin barrier more “leaky”, potentially allowing in more of the allergen, while at the same time allowing water to escape, leaving the skin dry and scaly.
The dryness causes itchiness but scratching further damages the skin barrier, worsening the process and setting up a vicious cycle (8).
Causes
Unfortunately, the incidence of atopic eczema in the world is still on the rise and the exact cause of eczema remains unknown. Treatments aim to relieve symptoms and reduce the severity and frequency of flares.
Genetics
Eczema often runs in families whose members have food allergies, allergic rhinitis (hay fever) and asthma. Infants with eczema have a greater chance of developing these other atopic diseases in later life provoking the “atopic march” theory (9).
It is now known about some of those genes that are associated with atopic eczema.
The most notable gene responsible for the condition is the FLG gene that encodes for filaggrin, a protein involved in water retention and is responsible for the skin barrier function.
Mutations in the filaggrin gene cause dry skin and, as a result, a strong susceptibility to the disease.
The lack of filaggrin can allow the entry of airborne allergens to enter the skin which can lead to an inflammatory response by the immune system (10).
It is important to note that eczema IS NOT contagious.
Environment
Some people have an abnormally sensitive immune system that is allergic to the surrounding environment or to certain substances known as "allergens”, but some of these substances are not harmful to humans.
Sensitization varies from person to person, but flare-ups can be triggered by contact with:
Cigarette Smoke
Dust
Mould
wool and nylon
Clothing Fabrics
Dust Mites
Perfumes
Deodorants
Fur
Pollen
Detergents
nickel and cobalt
Metals
Soaps
A theory popularized in recent years, called the hygiene hypothesis, refers to when children are not given an opportunity to be exposed to bacteria due to excessive cleanliness. When this occurs, the immune system cannot differentiate between a real threat and a harmless substance. This increases susceptibility to allergic diseases by suppressing the natural development of the immune system (11).
Avoid all these and dress in soft fabric.
Change in weather
The role of environmental factors in the pathogenesis of eczema is also very important. Changes in the weather, overheating, excessive sweating and low humidity can also contribute to the flare-ups.
Avoid overheating and don’t get too sweaty.
Treatment
#1 Creams
Topical medications are the primary choice of treatment. However, with creams, you are not looking at the underlying root cause, but these can control the itchiness and inflammation. Always consult your doctor before applying such creams.
Topical corticosteroids
Topical corticosteroids are generally used on the affected area, but their application can accompany some side effects.
Common side effects: skin atrophy, stretch marks, depigmentation, perioral dermatitis, acne rosacea, bacterial infections, withdrawal effects, striae development, growth retardation, osteoporosis and adrenal suppression (12).
There are differences in these steroid creams in terms of the potency (the strength of their effect).
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Low-potency corticosteroids: hydrocortisone and prednisolone
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Moderate-potency corticosteroids: prednicarbate, methylprednisolone and triamcinolone.
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High-potency corticosteroids: betamethasone and mometasone.
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Ultra-high-potency corticosteroids: Clobetasol (13)
The high potency of such creams should be avoided on severe lesions only. These should be limited to the use of thin skin such as the face or skin folds. It is not recommended to use these for two consecutive weeks (14).
Topical calcineurin inhibitors
If for some reason steroids shouldn’t be used, there are another class of non-steroid creams with fewer side effects known as topical calcineurin inhibitors. These include Elidel (Pimecrolimus) and Protopic (Tacrolimus), which are used in acute attacks. These alter the immune system response to prevent flare-ups.
Tacrolimus seems to have an anti-inflammatory potential similar to corticosteroids but pimecrolimus is not as effective in treating severe eczema (15).
However, studies have reported that is safe to use the tacrolimus and pimecrolimus for up to 2 and 4 years, respectively (16, 17).
With this said, there are still concerns by the FDA with cancer risk associated with their use, but the claims are still unproven (18).
Side effects: transient burning and itching sensations
Antihistamines
Other treatments include antihistamines to reduce the itching sensations. These aren’t always prescribed to patients as their efficacy are not proven by trials (19). This is due to the fact that eczema is not really a histamine problem, but the sedating effect can reduce the scratching which indirectly helps with eczema.
Only the first-generation drugs such as Benadryl (diphenhydramine) and Chlor-Trimeton (chlorpheniramine) carries these sedating properties and hence, second-generation drugs like Claritin (loratadine) and Zyrtec (cetirizine) are less likely to have an impact (20).
If severe atopic eczema occurs, local treatment may be ineffective. You can, however, consider immunosuppressants such as azathioprine, cyclosporine and methotrexate which are taken orally that helps suppress the immune system. However, these medications are not approved by the FDA specifically to treat eczema (21). Antibiotics can help to treat infections if they are needed.
#2 Skin care
Genetic factors or poor immunity can lead to insufficient production of natural oils causing skin dryness. As the skin barrier is broken down, the goal is to get moisture back into the skin and to create a barrier to protect the skin.
Dry skin can be managed with frequent moisturisation which is best to apply immediately after a lukewarm bath.
Do not overheat the bathing water and avoid soap as it will take away the body’s natural oil. Apply the moisturizer after the prescription topical medication if used.
The best moisturizer to treat eczema are the oil-based ones as they can keep moisture in and irritants out.
Generally, for eczema patients:
oil-based
Ointments
Creams
water-based
Lotions
Burt's Bees Hand Salve works well against eczema
Use oil-based, fragrance and dye free moisturizers to prevent irritation and keep the skin hydrated
Keep your fingernails short and try not to scratch the itchy skin
#3 Food
Foods are among the many environmental factors that contribute to aggravating eczema. The antigens concerned are usually in gluten, fish, shellfish, eggs, peanuts, tree nuts, wheat, soy and milk (22). you can eat more foods packed with anti-inflammatory foods to strengthen your immune system.
A detailed article will be written about food and eczema.
Everyone’s different and removing all these food items is extremely difficult to achieve an overall balanced diet. A practical approach is to try the elimination diet. You can remove the suspected food items in your diet for two weeks and then slowly reintroduce them over time to see if the food causes any reaction in the body (23).
Note that removing nutritious foods from the diet means that you need to substitute with one that is equally healthy. Hence, this process is best done and supervised by a registered dietitian.
#4 Stress
The cause of eczema may be stress related, and many patients experience deterioration of their condition due to emotional stress. Theoretically, when we are experiencing a stressful situation, our bodies enter a flight or fight mode. Our body then increases the production of cortisol, a stress hormone, but the excess levels of cortisol can suppress the immune system and cause an inflammatory response in the skin (24).
Eczema sufferers are often diagnosed with anxiety and depression (25). This is due to the fact that there are still a lot of social stigmas associated with it as it affects the physical appearance of someone. This can affect self-confidence and easily lead to social isolation.
Therefore, eczema patients with emotional or psychological patients should try to alleviate stress by practising relaxation techniques. Counselling can be extremely beneficial to break the itch and scratch cycle (26).
Exercise, meditation, yoga, reading, massages, support groups, counselling, having enough sleep