I've just started the allergy shots for my frenchie mix. It's too early to see any changes but I really hope there is some relief for him in the future. He doesn't have food allergies (but we are still feeding them Fromms pork and peas because the quality if food is just better).
In conjunction with the shots we still need to give him oral meds (atopica) and a topical med (medicated shampoo). Again like others mentioned the vet said it would take about a year to see any results. One of our problems is we are a military family so we are moving soon next year so he will then be exposed to other things he is allergic to so we may need to start this process over again. Totally will be worth it if he starts growing his fur back around his chest and neck again.
I rehomed a bully with skin & fur problems and after other food trials
put him on Avoderm's Grain Free kibble. In about 3 months his fur had
filled in the bald spots, thickened up all the thinning areas and become
shining & full with less shedding and the white just glowed!
You might add avocado to his Fromms as that is what it's based on.
Give a couple of slices twice a day as a topper, about a half total.
Do not be afraid of myths they are poison to dogs, just don't give pits.