Eczema appears as sore, itchy, red patches on the skin, often with tiny blisters (also called vesicles). The rash usually affects the back of the knees, the creases of the elbows and the face and neck. Sometimes, in severe cases, it also appears on the torso.
The itching of eczema can be intense. Sufferers - especially young children - tend to scratch the inflamed patches. When scratching is hard enough to break the skin, the inflamed area may also become infected. In the long run, repeated scratching can lead to permanent skin thickening.
Sources
http://www.familyhealthguide.co.uk/eczema/symptoms.html (last accessed May 2010)
http://www.nhs.uk/Conditions/Eczema-(atopic)/Pages/Symptoms.aspx (last accessed May 2010)