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Eczema is a common chronic skin condition. In Hong Kong, roughly one in five people suffers from eczema at different periods of their life. It is the most common paediatric skin disease, affecting 30% of children in Hong Kong and 15-20% worldwide.
Eczema is a dermatologic condition bringing inflammation, itchiness, redness and dryness in any skin areas of the body. Sometimes, cracked scaly patches and blisters can occur. Eczema affects people of all ages, but it usually appears within the first year of life and before the age of five in most cases. It can extend to adulthood. Eczema is more common in women than in men. Some people will outgrow eczema at some point, some will have improved symptoms at times, while others will continue to experience eruptions throughout their life.
Eczema is not contagious, so one needs not worry about daily physical contact with eczematic patients. Currently, there is no cure yet for this common skin disease, but it is still manageable in many cases.
The terms eczema and atopic dermatitis are often used interchangeably, which can be confusing. There are actually seven types of eczema and atopic dermatitis is one of them. Others include allergic contact dermatitis, dyshidrotic eczema, neurodermatitis, nummular eczema, seborrheic eczema and stasis dermatitis.
Atopic dermatitis is the most common form of eczema, particularly in children, and a severe chronic disease itself. When people talk about eczema, they usually mean atopic dermatitis.
Allergy, according to the Australasian Society of Immunology and Allergy, is an immune reaction to allergens which are harmless substances that cause no reaction to most people, for example pet dander and chemicals in soaps and detergents.
Not all types of eczema are allergies. Eczema can be triggered by factors other than allergies. However, symptoms can get worse or a flare-up can occur when the skin is in direct contact with allergens. Due to the lack of filaggrin (a protein that is a structural component of our skin) in people with eczema, their skin becomes more sensitive and leaky that allows allergens in easily as well as water loss.
Atopic dermatitis and allergic contact dermatitis are two types of eczema that are related to allergies. Atopic means tendency to develop an allergic reaction. As the name suggests, allergic contact dermatitis is a skin disease that appears when the skin is in contact with allergens.
The signs and symptoms of eczema vary between individuals. Sometimes they come and go quickly, sometimes they just persist for a long time. The affected skin areas could also change at different times. General signs and symptoms are:
Infants (0-2 years old)
Children (2-12 years old)
Adults (puberty onwards)
The cause of eczema is not known. Some suggestions include:
Eczema can also be triggered by the following:
Bacterial skin infections
There are countless bacteria living on our skin and one of them is Staphylococcus aureus. They do not normally cause any infections. People with eczema may have breaks on the skin easily that allow bacteria to enter our bodies and infect our skin, causing yellow crusting. Antibiotics are usually given as a treatment.
Viral skin infections
People with eczema are also vulnerable to be infected by herpes simplex 1 virus that normally causes cold sores around or inside our mouth. It could develop into a much more serious infection called eczema herpeticum. Eczema herpticum presents as clusters of red, purple or black blisters that are painful and itchy, affecting a large area of skin. It can be potentially life-threatening. Patients will usually need hospital admission for isolation.
Apart from infections, people with eczema also suffer psychologically. As eczema affects appearance, children and young people may be subject to bullying in schools. They may tend to have a lower self-esteem and be prone to depression. In addition, itchiness can affect the quality of sleep at night, which may cause changes in mood and behaviours.
At present, there are no tests available to diagnose eczema. Your doctor is likely to do it by:
Eczema is not curable but still can be effectively controlled. Depending on the severity of symptoms, your doctor may provide you with the following management options:
Both topical and oral drugs are used in the management.
They are the most commonly prescribed and essential medications in the management. Creams and ointments are applied directly onto the skin for 1-2 times daily if needed. Increasing application frequency does not improve symptoms significantly. Oral corticosteroids are available for severe conditions.
However, long-term topical use causes side effects such as acne, skin thinning, rosacea and skin discolouration, and that of oral use are redistribution of body fats, high blood pressure and increased risks of infections. Examples of corticosteroids are hydrocortisone, betamethasone and prednisolone.
b. Topical calcineurin inhibitors
Cream containing calcineurin inhibitors is a prescription only medication for patients aged 2 years old or above. It is particularly beneficial for those who fail treatment with corticosteroid cream. It is also useful for managing eczema in delicate skin areas such as face and neck.
c. Anti-allergic drugs
Antihistamines can reduce itchiness, swelling and redness by blocking the action of histamine. Histamine is a chemical involved in immune response and allergies. Examples of antihistamines are cetirizine, chlorpheniramine, diphenhydramine, hydroxyzine and loratadine. Some of them can cause drowsiness.
If your skin has a bacterial infection, your doctor may recommend you to take topical or oral antibiotics. It is important to follow doctor’s instructions to finish the whole course of treatment.
e. Immunosuppressive agents
They work by suppressing the overactivity of the immune system and therefore relieve the symptoms. This class of drugs is very potent. So, it is the last choice when other medicines fail and for short-term use only. As they curb the immune system, one of the side effects is greater risks of getting infections. Examples include cyclosporine.
2. Skin care
Emollients are moisturizing agents, often as cream, ointment or lotion, that act as a thin oily film to seal water in the skin. They maintain skin hydration, and therefore to relieve dryness and itching. One thing to bear in mind is not to apply emollients on inflamed skin. You should apply emollients at least three times a day including after bathing.
There are a variety of dressings, such as dry wrap dressings and occlusive dressings to prevent scratching and to help emollients stay on the skin longer for better effects.
Phototherapy (light therapy) works by curbing the immune system from being overactive to reduce rash and itching. The more common type is to use narrow band UVB (ultraviolet B) as a long-term treatment to induce a stable skin condition with minimal symptoms. Another one is called PUVA, which is a combination of psoralen (an oral or topical light-sensitive agent that absorbs UV light) and UVA. PUVA may help with clearance of eczema but the risk of developing skin cancer is higher, so it is for most severe patients only.
Diluted bleach bathing (~0.005%) can improve eczema by reducing the amount of bacteria on the skin. To do it, add half a cup of bleach (sodium hypochlorite) to a full standard bathtub of water for 2 times a week.
Some people may find natural alternatives and other kinds of therapies useful in managing eczema, for example herbal medicines, massage and aromatherapy. However, there is no sufficient or strong scientific evidence in supporting their use.
Stress can affect our immunity. Reducing stress and maintaining a cheerful mood may reduce chances of recurring symptoms.
This article was medically reviewed by Dr. Nicola Chan 陳珮瑤醫生 on July 29, 2019. Dr. Chan is a Specialist in Dermatology in private practice, based in Hong Kong. She graduated from the University of Cambridge, UK, and received post-graduate medical training in Cambridge, London and Hong Kong. This was followed by further laser and aesthetic dermatology training in Boston and Baltimore, USA. Dr. Chan is a member of the Hong Kong Society of Dermatology and Venereology, American Society of Laser Medicine and Surgery, Asian Dermatological Association, and Hong Kong College of Dermatologists.
This article was independently written by Healthy Matters. It is informative only and not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be relied upon for specific medical advice.
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