Eczema is of several types (such as allergic contact eczema, atopic eczema, discoid eczema, irritant contact eczema, seborrhoeic eczema) but the symptoms of different forms of eczema can be generalised. Whatever the cause, eczema is causes, in varying degrees, symptoms such as:
Itch: This is the major symptom of eczema. If a rash is not associated with itch it is not due to eczema (unless the itch has been improved by treatment). Although itching is an ‘essential’ symptom when diagnosing eczema, it can be caused due to many other skin conditions. That is why itching cannot be considered a symptom specific for eczema.
Redness: Redness of the skin is caused because of inflammation and increased blood flow. There is an extensive network of tiny blood vessels known as capillaries, in the deeper layers of the skin from which loops of smaller vessels go into the more superficial layers. Inflammation in eczema is caused because of a range of factors but an important reason when eczema flares up is the presence of bacterial infection. Recognising and treating infection appropriately is important to control and cure eczema.
Thickening: The skin affected by eczema with inflammation for sometime becomes thicker than the unaffected skin. This occurs as a protective response of the skin to repeated trauma of scratching. Eczema often occurs in skin around joints such as the elbow, behind the knees and in front of the ankles (the ‘flexures’) where the skin should be particularly flexible. Prolonged inflammation and thickening often causes split in the skin—called fissures—as the thickened skin is unable to bend as it would normally.
Blisters: Blisters may be seen in active eczema. They are usually small but occasionally large ones may occur. Large blisters are formed in some types of eczema or may be formed because of skin infection. Infected blisters may be filled with clear fluid or pus.
Crusts: Fluid oozes from inflamed skin in eczema. It is rich in protein and hence when it dries on coming in contact with air, only protein is left behind, forminga crusty deposit. This often occurs when the skin affected by eczema becomes infected. The infected crust typically has a golden colour.