My dog also has allergies. We have had 2 incidences of hot spots. What works best for us is to cut the hair around the sores, so it can breathe and apply a mixture of herbs and tea to the sores. It cleared up much faster than with the topical antibiotic.
Boil water and add pau d'arco, olive leaf and chamomile tea. Let steep until water cools and keep in refrigerator for up to 3 days. Apply when needed.