Eczema is one of the most common skin disorders in infants and children. Apart from dealing with the medical aspect of the disease, affected patients may experience significant psychosocial effects.
Also termed as atopic dermatitis, it is very common in children but may occur at any age.
How does atopic dermatitis arise?
Atopic dermatitis is caused by a complex interaction of genetic and environmental factors including:
- Skin barrier dysfunction
- Genetic predisposition
- Immune dysfunction
The role of genetics in eczema
Most patients with eczema have a lower amount of filaggrin in the epidermal skin layer., due to mutations in the filaggrin gene. Filaggrin is a structural protein that plays a vital role in normal barrier structure and function. A lack of filaggrin contributes to the development of eczema in several ways.
Filaggrin breaks down into amino acids and protein derivative to form natural moisturizing factors (NMFs) in the outer skin layers. NMFs provide moisture retention, maintain the acidic pH and buffering capacity of the skin barrier and prevent an overgrowth of bacteria.
Inadequate filaggrin would mean a reduced ability to maintain hydration, which can cause xerosis (dry skin), pruritus (itching) and subsequently, eczema. A dysfunction in skin barrier may also allow entry of allergens, leading to an inflammatory response thus causing eczema.
Having an impaired barrier function also causes colonisation of a bacterium called Staphylococcus aureus. Scratching disrupts the skin barrier, thus also leads to the bacteria adhering to the outer skin layers.
The extent of bacterial colonization is associated with the severity of eczema.
How immune dysfunction contributes to eczema
Apart from genetic factors, defects in immune pathways are usually observed in patients with eczema. They tend to have high levels Th-2 cells, which contribute to a defective skin barrier. Th-2 cells play an important role in the immune system. A poor skin barrier may mean water is lost from the skin and also allows the penetration of irritants (soap, dirt, detergent) and allergens (pollens, microbes, dust-mites).
There is also an overproduction of cytokines in the body. Cytokines are cell signalling molecules that aid in cell to cell communication. It regulates the movement of cells towards sites of inflammation and infection.
The excessive release of cytokines initiates new responses that eventually leads to inflammation, causing the red, itchy and painful symptoms common in eczema.
Patients also have high levels of an antibody called immunoglobulin E (IgE), which puts them at disposition for hypersensitivity to environmental allergens. Hypersensitivity is when the immune system produces undesirable or detrimental reactions, such as attacking the body’s own cells or tissues instead of protecting them. With elevated IgE levels, it would mean exposure to a certain allergen can causes the immune system to attack the body’s own tissues and therefore skin inflammation that may be observed with eczema patients.
How to treat eczema?
When it comes to treatment, there are 3 main components that target a specific manifestation of the disease. As a chronic, relapsing condition that may flare up at variable intervals, a comprehensive home treatment plan is important for successful management.
Repair & Maintain Healthy Skin Barrier:
Patients with eczema should use moisturizers that are fragrance-free and least amount of preservatives, as these are potential irritants.
Topical corticosteroids are the most effective and common treatment. Corticosteroids are drugs that mimic cortisol, a hormone found in the body. They work by diminishing inflammation, itching and bacteria colonisation.
This medication can be classified according to its potency, ranging from class VII (low potency) to class I (super potent). Great care must be taken to balance the potency of drug needed for results so as to minimise potential side effects.
Side effects include:
- Atrophy (decrease in size or wasting away of a body part/tissue)
- Striae (stretch marks)
- Telangiectasisa (small dilated blood vessels)
- Secondary infections
- Adrenal suppression (body produces lower levels of cortisol)
For moderate to severe eczema conditions, wet wrap therapy can be used with topical steroids and dermatologist-approved moisturisers. After the medication is applied to the affected area, it is wrapped with a few layers of wet gauze, followed by dry gauze. Such therapy reduces itching and inflammation by preventing scratching and improves penetration of corticosteroids.
Topical inhibitors of calcineurin – protein phosphatase associated with activation of the immune system, are newer forms of treatment, which are considered on areas unsuitable for topical steroids (e.g. eyelids) or if other treatment options do not yield results. For example, Pimecrolimus cream and Tacrolimus ointment are calcineurin inhibitors that have demonstrated good efficacy for eczema treatments and do not cause side effects that corticosteroids bring, but have other considerations of use that should be managed with an accredited dermatologist.
Antihistamines are commonly used to treat itching. Even without a significant rash, itching can be present. Oral antihistamines help to reduce the sensation of itching, ideally to decrease scratching and trauma to the skin.
Antibiotic or antifungal medicines are used to treat the infected rash, to reduce the amount of bacterium Staphylococcus aureus. Topical mupirocin is often prescribed to prevent further infection.
Taking care of the skin
Avoid dry skin. Asian skin is more susceptible to being dry. Dry skin can cause itching and scratching. Tips to avoid dry skin:
- Moisturize, especially after a bath as evaporation can cause excessive drying. A moisturizer that is suitable for sensitive skin would be Radiance Fluide™ Hydrating Emulsion.
- Bathe with lukewarm water for 10-15 minutes.
- Use neutral or weakly acidic pH soap. Consider a mild cleanser that soothes the skin like Le Lait™ Milk Cleanser.
- Avoid high ambient temperatures.
Avoid irritants that can cause or aggravate a rash, such as perfumes, scratchy clothing or bedding and sweating.
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Meet with Dr. Teo Wan Lin, an accredited dermatologist at TWL Specialist Skin & Laser Centre, for a thorough consultation to determine the most suitable treatment for your skin.
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Tags: acne, eczema, Eczema Treatment, itch, skin barrier