Last updated on May 6, 2021.
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.
What is Eczema?
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.
Eczema vs Atopic Dermatitis
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.
Eczema and Allergy
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.
Signs and Symptoms
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:
- Dark colored and thickened patches
- Rough, scaly or leathery patches
- Crusting and oozing
- Dry and sensitive skin with swelling and blisters
- Usually mild to moderate itchiness
Infants (0-2 years old)
- Usually appears on the face (often the cheeks) and hands
- Red rashes appear on forearms and legs when babies start to crawl
- Extremely itchy skin leads to sleep disturbances and bleeding due to scratching
- Blisters and oozing
Children (2-12 years old)
- Rashes are common on neck, ankles, wrists, backs of knees and insides of the elbows
- Significant redness, dryness and scaling
- Thickened skin and skin-picking
- Darkened or lightened skin colour
Adults (puberty onwards)
- Some will completely clear off eczema and have no more symptoms
- Others follow a cycle of recurrence and remission
- Usually manifest as hand eczema
- Rashes also occur in skin areas around the eyes and forehead.
Causes and Risk Factors
The cause of eczema is not known. Some suggestions include:
- Overactive immune system: inflammatory responses are triggered by irritants easily, resulting in rashes and itchiness.
- Abnormal skin barrier: this allows moisture, allergens, bacteria and viruses to enter the body easily and gives extra-sensitive skin.
- Heredity: children are at an increased risk of developing eczema if parent(s) also have it.
- Family history of other allergies: children are more likely to develop eczema if their family members have allergies such as hay fever and asthma.
Eczema can also be triggered by the following:
- Environmental allergens: e.g. dust mites, pets, pollens, household irritants like detergents, shampoos and soaps.
- Proteins in food: e.g. eggs, nets, beef and dairy products.
- Stress: there is no direct relationship between stress and eczema, but it can worsen the symptoms.
- Hormones: there may be a flare-up or worsening of symptoms when the amount of hormones in the body changes, especially in women.
- Dry skin
- Heat and sweat, cold dry weather
Complications of Eczema
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.
How to Diagnose it
At present, there are no tests available to diagnose eczema. Your doctor is likely to do it by:
- direct examination of the affected skin area;
- reviewing medical and family history;
- asking you questions to rule out other possibilities that may have contributed to the symptoms;
- referring you to a dermatologist to confirm the diagnosis;
- performing an allergy testing to determine any triggering factors.
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.
Self-care and Daily Management
- Take a bath or a shower using lukewarm water. Avoid long baths or showers. Do not scrub the skin too hard during bathing or showering to avoid skin irritation.
- Dry the skin after cleansing by gently patting.
- Avoid using perfumed or scented cleansing agents or moisturizing cream.
- Choose purer cotton and lose-fitting clothings.
- Keep a tidy and clean household to avoid dust and house mites.
- Maintain a balanced diet to improve immunity.
- Keep your nails short to minimise scratching.
- Avoid contact with any known allergies to your skin.
- Avoid activities in strong sunlight as excessive sweating can worsen skin irritation.
Stress can affect our immunity. Reducing stress and maintaining a cheerful mood may reduce chances of recurring symptoms.
Useful Resources in Hong Kong
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.