My ferret is scratching her cut?

I have a 4 year old ferret. Very recently, my boyfriend noticed that she was scratching herself more than usual. When he went to check it, he found a cut that was scabbed over which she continued to pick at. My immediate assumption was that she might have fleas. I immediately gave her a flea bath, however I don't think I saw any fleas in the water or in her fur when I checked. Has anyone else experienced something similar with their ferret? I don't want to bring her to the vet without good cause. Thanks!