Since I am not a doctor and don't know the CAUSE of the sores, I can only make some common-sense suggestions to you. I believe that you need to find the cause of the sores in order to find out what medication will help prevent them. Sores can be due to blood sugar levels that are not in control, fungus, allergies, or any number of things. Obviously, the first thing any doctor is going to do is to try to help you get the best possible control of your diabetes. So that much is probably a "given" -- if you need to tighten up your control, then you can do this first. This means trying to keep your glucose numbers in the normal range as much as is possible. Good control over your diabetes will give you healthier skin and of course healthier circulation and healthier major organs, too.
Other than this, your doctor can probably look at the sores and determine from their appearance what their cause is. He may have to try several different treatments to find one that works best for you.
But I don't think anyone other than your doctor is going to be able to suggest medications that will miraculously stop any kind of sore from appearing without doing an examination and probably running some tests to try to determine what the real cause is. Your doctor probably will want to do a blood test (an a1c test) to see how good your glucose control has been so that he can tell whether poor glucose control is a factor at all in the development of these sores.
If your control is great and the sores are due to something else, your doctor is really the person who can best find out what it is that is causing them. I hope you can find some relief soon.
I always thought these things happened to others! I have had the worse time over the past 6 months with chills, sweats, fatigue, thirsty all the time and not to mention the worse itching in my genital area. I finally went to one of those emergency clinics because I was in tears going to the bathroom and the doc there didn't know what kind of rash I had but he treated me for a yeast infection and herpes. I do not have herpes, and I felt better for a couple of weeks then I started breaking out on my buttocks, in what I thought was a heat rash,then the bumps started turning into boils but they weren't too bad I chalked it up to working in the heat and given time they went away until this last one in my groin that got sooo infected over the weekend, it was the size of a egg, and I had fresh bumps appearing all over and they burned more than itched.
Anyway my stubborn, bumpy butt went to a real doctor and the first thing out of his mouth when he saw my sores was "Have you been checked for diabetes?" My heart sunk! However, I now have relief in knowing that these sores got me to the doc and I am on Keflex antibiotics and am waiting for my test results, which I will get tomorrow. (Not to mention he had to cut open the boil and drain it!!It hurt worse than child birth)
I am reading all I can about this and I have had theses symtoms for years and I can't imagion having a normal pain free life, I hope that it is not too late, but I will never wait 5 years again before going to a doctor.
Not to mention I turn 40 this year and people tell me with age certain illnesses will begin to surface, so I have to take care of my self. I guess we are all like engines over time wear and tear starts to take it's toll and certain parts need special attention. I look at it as my fluids are out of wack.
If I could do things over I would go to the doctor first. I never did because of having no insurance but when I add up all the money I spent on treating myself with ever over the counter meds, I could have gone and paid cash twice for a good doctor.
Now days with all the skin diseases going on everyone should take any out of the ordinary rash straight to the doc!