We recently went through this with Maeve and Fiona, the grown goldens. Took Fiona to the vet because she was really suffering.

Turns out that it was allergies to the flea bites. I don't like putting chemicals on the girls, so I haven't been using the K-9 Advantix that the vet prescribed. Well, all three got dosed with with as soon as Brian brought Fiona home from the vet. The vet said to use it every 3 weeks during the summer months instead of once a month. In any case, the itching has decreased significantly since we applied the Advantix. No new hot spots and the ones they had are healing. They are much, much more comfortable.

AdvanTIX is much better than Advantage, by the way. They've had ticks, too, and I've removed two attached ticks from myself this summer.