Ouch! That irritation can be a number of things, including an allergic reaction, injury trying to heal, infection from bacteria, fungus, or yeast, and more. Since it can be so many different things, a vet visit in person is best. It's also a good idea to place an Elizabethan (cone) collar on Alley to keep her from licking and chewing the spot to see if that helps reduce the irritation. Keeping the area clean and dry can also help.
If the spot doesn't seem to look better in 24 hours, worsens, is oozing debris or seems painful/bothersome, or is causing Alley distress, then a vet visit is best to have the area looked at in person and a sample taken to check for the underlying cause. As some fungal infections can also transfer to other pets and people, it's a good idea to wash hands and clothing after handling it as well.