What's a good home remedy for itching cause by foot ulcers?

Rest: If you have an ulcer to your foot, you should try to stay off of the area/ulcer as much as possible. For the itching itself, try some lanocaine, or Benadryl (diphenhydramine) cream. Remember that itching can be a sign of healing. If unsure, contact your physician.

Many possibilities: There are many things that could cause the skin to itch. Several types of inflammatory conditions of the skin, allergic reactions, and sometimes bacterial, viral or fungal infections can cause rashes on the skin. Have it evaluated by a professional and get the appropriate treatment.