Has anyone used immunotherapy for the treatment of allergies?

I was looking for advice as my dog is having this treatment. He has recently had his third injection. He is allergic to dust and storage mites.

I have noticed an improvement in his symptoms, however, he now has severe inflammation on his legs, flank, chest, muzzle and right eye, which is causing a lot more bald patches to appear and he is miserable.

My question is will his skin get worse before it gets better? Any advice appreciated.

My dads dog had it for several months & sadly she had no improvement whatsoever, in fact I think she was worse, the vet kept telling dad to keep her on it but after nearly 18mths he gave up, I personally think the vet was on the fiddle with it but thats another story!

Thanks for the response. my vet has said it could take up to 6 months before we see any improvement. Coles was on 10mg of steroids everyday and had been for the last year and a half. however, after his second injection of immunothreapy, his symptoms appeared to be a lot better so I reduced it to one 5mg tablet a day. He was at the vets on Saturday just gone and the vet has asked that I give him one 5mg steroid every other day to see if the treatement is working. although I have seen improvement i.e not licking all over constantly, He is skin is looking really sore and inflammed. albrit, he is licking where the inflammation is now, but he's no bothering to lick himself all over constantly like he used to. He's back at the vets in two weeks for another injection and I think I will ask the question will the inflammation get better over time. This poor dog, I feel so sorry for him at the moment.