Why does my dog keep scratching this one spot in her back?

She's been scratching for a few days now on her back but only one spot, and I checked for ticks or fleas but I found nothing, but I found this tiny spot that was red and it seemed to have a little blood but nothing serious. What can I do and what could this be?Thanks a lot for the answers :)Thank you so much

Clean the spot with alcohol.. Put on some Neosporin and keep an eye on it. If it doesn't get better than take the dog to the vet.

sounds like a hotspot...mine get them in the summer while its hot...or when they are ready for new flea meds..try some alcohol...and if it gets that bad call a vet and theyll give you infoadd: - a hot spot treatment is mercaptobenzothiazole...(off the bottle from VET) and my dogs respond better to alcohol than the stuff from the vet...and the stuff from the vet smells stronger than alcohol and burns if you have cuts while you put it on...so as for alcohol irritating it....yeah, for a minute, then it evaporates and the dog forgets about it. just as you would if you cleaned a wound with alcohol

DO NOT CLEAN THE SPOT WITH ALCHOL!!!!This will only irritate it.You can clean it with betadine or something much less harsher then alchol Then put some hydroquartizone. This will help ease the itching and lessen and inflammation. if it gets bigger go to a vet.