I just did I search and I think it is, because:

Dogs most susceptible to hot spots are those with heavy coats and histories of allergies, ear infections, flea infestations, irritated anal sacs, and grooming problems such as hair tangles and mats, but any dog can develop this infection. Dogs in warm, humid climates may develop hot spots when they shed their undercoats if the dead hair is trapped next to the skin, and dogs with behavior problems may mutilate themselves by licking and thus encourage an infection to become established


Katie has a heavy coat, and has a history of allergies, it has also been very hot this past week because we didn't have a/c and she was panting and licking herself.

so it could be it