Hi there and thanks for your question.
How long has your dog had these sores?
OK. Thanks for the extra information.
This will be hard to say for sure without actually examining your dog, but what you have described sounds like a bacterial skin infection. The good news is that this is likely not terribly serious. The bad news is that skin infections always need oral antibiotics prescribed by the vet in order for it to go away. If it is a skin infection you probably don't need to run her into the vet today unless she is really uncomfortable. You mention you have tried benadryl. Here is some information on benadryl just so you can be sure you are giving her enough:
Another possibility is that this is an allergic reaction to some insect bites, but really it shouldn't cause her that much discomfort and the benadryl should help.
So, hopefully she can get to the vet's soon, but again, it is not something you would need to go to an emergency clinic for.
I hope this information helps! If you have more questions regarding this problem, just hit reply. If I am online I will respond right away. Otherwise I will respond as soon as I come online again. Or, if my answer is sufficient, then please hit accept. Thanks!