Eczema is "a general term for any superficial inflammatory process involving the epidermis primarily, marked early by redness, itching, minute papules and vesicles, weeping, oozing and crusting, and later by scaling, lichenification and often pigmentation."1 It is also used specifically to refer to the condition atopic dermatitis.
The word eczema comes from the Greek word ekzein meaning "to boil out"; the Greek word ek means "out," while the Greek word zema means "boiling."
Contents of this article:
You will also see introductions at the end of some sections to any recent eczema developments that have been covered by MNT's news stories. Also look out for links to information about related conditions.
Fast facts on eczema
Here are some key points about eczema. More detail and supporting information is in the main article.
- Eczema affects an estimated 9-30% of the US population.2
- People living in dry climates and cities appear to be more likely to develop eczema.2
- Eczema occurs equally in both males and females.2
- Eczema is likely related to conditions that adversely affect the skin's barrier function (including genetic factors, nutrient deficiencies, bacterial infection, and dry, irritated skin).9
- Stress and other emotional factors do not cause atopic dermatitis, but they can make the condition worse.2
- Certain foods such as nuts and dairy can trigger the symptoms.5
- Eczema can also be triggered by environmental factors such as smoke and pollen.5
- Atopic dermatitis has strong connections with other atopic diseases, such as asthma and hay fever.5
- Children with ADHD, or who attend day care have a higher risk of atopic dermatitis.9
- Treatment focuses on healing damaged skin and alleviating the symptoms.7
- There is no single test that can be used to diagnose eczema.2
- For some eczema will disappear completely, but for others it remains a lifelong condition.8
What is eczema?23
Common symptoms of eczema include areas of thickened, red, itchy skin.
The term 'eczema' is used in two different ways. It can be used widely to describe any rash-like skin conditions. It is usually used specifically to refer to the most common type of these skin conditions: atopic dermatitis.
Atopic dermatitis is a chronic skin condition that commonly starts during infancy and continues through into childhood. Some people outgrow the condition while some people will continue to have it into adulthood.
The word "atopic" refers to a collection of immune-mediated diseases, including atopic dermatitis, asthma and hay fever, to which a person can inherit a predisposition. "Dermatitis" means inflammation of the skin.
Types of eczema
There are many different types of eczema. This article will predominantly focus on atopic dermatitis. Other variants include:2
- Allergic contact eczema (dermatitis) - a reaction where the skin has come into contact with a substance that the immune system recognizes as foreign
- Contact eczema - a localized reaction where the skin has come into contact with an allergen
- Dyshidriotic eczema - irritation of skin on palms of hands and soles of feet, characterized by blisters
- Neurodermatitis - scaly patches of skin on head, forearms, wrists, lower legs caused by localized itch such as an insect bite
- Nummular eczema - circular patches of irritated skin that can be crusted, scaling and itchy
- Seborrheic eczema - oily, scaly yellowish patches of skin, usually on scalp and face
- Stasis dermatitis - skin irritation on lower legs, usually related to circulatory problems.
This video by the Eczema Society of Canada explains what eczema is and why it occurs.
Causes of eczema23
Pollen is one of the most common eczema allergens.
The specific cause of eczema remains unknown, but it is believed to develop due to a combination of hereditary and environmental factors.
Children are more likely to develop eczema if a parent has had it or another atopic disease. If both parents have an atopic disease, the chances increase further.
The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) report that approximately half of children who develop atopic dermatitis go on to develop one of the other atopic diseases.
Environmental factors are also known to bring out the symptoms of eczema.45 These include:
- Irritants: soaps, detergents, shampoos, disinfectants, juices from fresh fruits, meats or vegetables
- Allergens: dust mites, pets, pollens, mold, dandruff
- Microbes: bacteria such as Staphylococcus aureus, viruses, certain fungi
- Hot and cold temperatures: hot weather, high and low humidity, perspiration from exercise
- Foods: dairy products, eggs, nuts and seeds, soy products, wheat
- Stress: it is not a cause of eczema but can make symptoms worse
- Hormones: women can experience worsening of eczema symptoms at times when their hormone levels are changing, for example during pregnancy and at certain points in their menstrual cycle.
Recent developments on eczema causes from MNT news
Mouse model developed for atopic dermatitis. A study reports the development of a new mouse model for atopic dermatitis, an inflammatory skin disorder commonly known as eczema.
Eczema may be linked to antibiotic use in babies. Researchers publishing in the British Journal of Dermatology has found that the use of antibiotics in babies may increase the risk of developing eczema by up to 40%.
Scientist identifies pivotal cellular protein underlying eczema. Researchers from the La Jolla Institute for Allergy and Immunology have revealed a critical player in the cellular interactions leading to eczema.
On the next page we look at the signs and symptoms of eczema, tests and diagnosis and the possible options for treating and managing eczema.