What are the symptoms of eczema?
Whatever the cause, eczema leads to itching and redness, and may make the skin dry and flaky. Sometimes itchy blisters form. The surface of the skin may become moist and crusty if these blisters burst, or when scratching damages the skin. Atopic eczema is often worse in the folds of the skin where the limbs bend. The itch is intense, but scratching only makes
the symptoms worse. Eczema makes the skin more sensitive, so you may notice that you are more irritated by cosmetics, soaps, detergents, etc. Eczema in infants is most commonly seen as a patch below the chin or cradle cap.
Itch - This is the main symptom, and without it a rash is not due to eczema (unless the itch has been improved by treatment). Itch is also a common feature of many other skin conditions as well as being a symptom of a range of diverse medical conditions not primarily to do with the skin, so although it is an ‘essential’ symptom when diagnosing eczema it is not specific for it. We still do not fully understand what causes itch, but nerve fibres specialised in transmitting the itch sensation appear to exist within the skin. Like other nerves, these are ultimately connected to the spinal cord and so to the brain. It used to be thought that the sensation of pain travelled along the same nerve fibres as for itch but this seems now to be unlikely. Interestingly, the two sensations can act against each other. Thus relief from severe itching may sometimes be had from inflicting pain instead, as might be seen in someone who prefers the discomfort of a very hot bath to that of constant itching. The act of scratching may itself cause nerve signals to travel down the pain fibres, blocking the sensation of itch from being experienced.
Redness - Increased redness of the skin usually means increased blood flow. An extensive network of tiny blood vessels (capillaries) is present in the deeper layers of the skin that project loops of smaller vessels into the more superficial layers. The very top layer of skin is composed of dead skin cells and has no blood supply, so a superficial cut to this level will not bleed. When skin is inflamed the local network of blood vessels widens, increasing the flow of blood and making it red. The process of inflammation in eczema is complex and can be triggered by a range of factors but an important additional one to take into account when eczema flares up is the presence of bacterial infection. When bacterial infection gets into the deeper layers of the skin there is usually a marked increase in redness and heat from the tissues. Recognising that this may be due to infection is important in bringing the eczema under control.
Thickening - The skin of areas of eczema that have been inflamed for a while are usually much thicker than unaffected skin. Mainly this occurs as a protective response of the skin to the repeated trauma of scratching. Eczema often affects the skin in areas around joints such as the elbow, behind the knees and in front of the ankles (the ‘flexures’) where the skin also needs to be particularly flexible. Commonly one will see splits in the skin here (fissures), as the thickened skin is unable to bend as it would normally.
Blisters - The microscopic study of skin structure in eczema shows there is less adhesion between the skin cells, particularly in the upper layers of the skin. This contributes to scaling and makes it easier for skin bacteria to get into the deeper layers, between the gaps. It also makes it possible for tissue fluids to ooze between the cells and, if sufficient, to gather into collections or blisters. Small blisters may be seen in active eczema but occasionally large ones may occur, either due to the particular nature of the eczema or because of skin infection coming along as well when the blisters may be filled not only with clear fluid but also pus.
Crusts - The fluid that oozes from inflamed skin is rich in protein. When this dries out in contact with air the protein is left behind as a crusty deposit. Often this occurs in conjunction with infection, when the infected crusts typically have a golden colour. A similar crusting is seen in the infectious skin condition called impetigo, which is commonly seen in children of primary school age as it is easily passed on by touching. In impetigo treating the infection eliminates the problem, but it is of course only part of what's required in eczema. Often doctors refer to infected eczema as being 'impetiginised'.
More information on eczema
What is eczema? - Eczema is a heterogeneous group of different non-infectious skin diseases. Eczema occurs in both children and adults, but usually appears during infancy.
What types of eczema are there? - There are various types of eczema, including atopic eczema (atopic dermatitis), contact dermatitis, varicose eczema, discoid eczema, nummular eczema, stasis dermatitis.
What are the symptoms of eczema? - Symptoms of eczema are itching and redness, and may make the skin dry and flaky. Eczema makes the skin more sensitive.
What causes eczema? - The most common cause of eczema is a general allergic over-sensitivity. Other types of eczema arise as a result of causes within the body.
How does eczema affect people? - In eczema, the main problems occur in the epidermis where the keratinocytes become less tightly held together.
How is eczema diagnosed? - Eczema is usually diagnosed through a physical examination. Further tests may include skin biopsy or patch tests.
What are the treatments for eczema? - Avoidance of the aetiological factors is one important therapeutical approach. Symptomatic treatment includes topical and systemic treatment regimens.
How can eczema be prevented? - Eczema flare-ups can be prevented by avoiding exposure to extreme temperatures, dry air, harsh soaps and bubble baths.
How to deal with infant or baby eczema? - For mild to moderate baby eczema, the application of moisturizer on a regular basis can be very helpful. Avoid as many eczema triggers as possible.
What is atopic eczema and its treatment? - Atopic eczema (atopic dermatitis) is the commonest form of eczema and is closely linked with asthma and hayfever.
What is dyshidrotic eczema? - Dyshidrotic eczema is a form of eczema often seen on the hands and feet where tiny blisters of serum form just below the skin's surface.
What is nummular eczema? - Nummular eczema is a chronic eczema characterised by coin-shaped, sharply demarcated lesions. Nummular eczema is more common in males.
What is hand eczema (hand dermatitis)? - Hand eczema, also called hand dermatitis, is a skin condition in which the hands develop a rash and become red, dry, cracked, and inflamed.
What is varicose eczema? - Varicose eczema is due to increased pressure within the veins in the leg. Varicose eczema affects the lower legs people in their middle to late years.
What's seborrhoeic eczema? - Seborrhoeic eczema is a common skin disease affecting any sebum-(natural oil) producing area of the skin.