Eczema and most skin based auto immune diseases spread from the first wound to surrounding areas. With eczema your skin goes really dry and there is an uncontrollable sensation to itch. Even if you have the greatest will power to resist the itch, you will find boils errupt in different parts of your body, as new hubs for the disease to spread. Its almost impossible not to indulge in itching, that is the only relief you will feel for a while, when you rip the top layer of your skin apart and bleed so you don't feel the itch but rather the burning sensation of your bloody wounds making contact with clothing. When it gets pretty bad you cannot wear clothing at night, always try sleeping in thin white cotton pajamas. In extreme cases, a strategy used with burn victims is to but them naked on banana leaves. That is a very useful tip as well. Once you've itched yourself to satisfaction and possibly peeled your top layer of skin, you will have the bad bacteria from the wound under your fingernails. This is how you may spread the disease to other parts of the body which were at first unaffected. While it is advised to wear gloves and not itch, I find it impractical as to how to not itch when you can't sleep as your body constantly demands to be itched.