Since you are unsure about where the irritation came from, I would be a little worried.
You can wash the feet well with peroxide or betadine and use a little antibiotic ointment (like neosporin) and wrap it loosely. A baby sock works really well with paw problems to keep it clean and protected. You can tape it loosely at the top of the sock to keep it on.
The most common cause of this crazy skin problems is an allergy problem. You might want to discuss getting a steroid shot (to give the skin time to heal) and the use of benadryl as an antihistamine with your vet. The typical dosage of benadryl is 1 mg per lb of body weight given every 8-12 hours as needed.
Thyroid conditions can cause unknown foot problem so you will want to have the vet pull a thyroid panel at your next visit if this continues to be a problem.
Let me know if you have more questions.
