I had a schnauser that was allergic to flea saliva. 1 flea bite and she would itch and scratch herself raw. Many hot spots, usually up around her neck. The vet gave me a hot spot spray which I think was a topical anesthetic but I also had to put a cone around her for a day or so to keep her from going after it. Hot spots become a downward spiral. They chew or scratch because they are irritated, but are irritated because they scratch and chew.