As requested Kiz.....I'll start from the beginning and try and keep it concise.
It started about 7 years ago when Doug was 2ish, with a red sore bald patch on tail.
Used a soothing cream and it cleared up.
Every year since then the problem has recurred.....usually starts late summer, lasts about 6-8 weeks and is gone by October.
Over the years, I've called it his 'seasonal allergy' and controlled it with creams......Dermacton is the current one I'm using.
This year the 'itch has gone out of control, starting early summer and it's still on-going now. Bald areas on tail, back, flanks and red sore belly.
I had to resort to the vets, as Doug was beginning to actually break the skin. We set of on an elimination route. I found fleas on one of the other dogs, but none on Doug so that's where we started.
August
1) Treated for fleas with diatomacious earth and the house and car were sprayed with Acclaim. Flea problem dealt with.
Doug still itchy so I gave Piriton, but it had little effect.
2)Vet said it was NOT a parasite or mites problem with Doug as it didn't look like it could be.

September
3)Doug has a steroid jab to try and break the itch/scratch cycle. He was itch free and his bald patches seemed to be recovering but 3 weeks later it all started again.
4) 10 day course of Prednicare, which worked quickly but 4 days after he finished the pills........
5)Itchy again and now scratching his muzzle and his ears. Back to vets.
October
6)Advocate to rule out any mites/fleas/worms. Ears checked,.......all clean and clear. Anal glands checked......1 was O.K. the other the contents not quite the right colour and a bit''gritty''. Possible precursor to infection.
Another 10 days of steroid.
Again the steroids quelled the itch till the course was finished then it 'back again.
7)Start using Malaseb shampoo 2-3 times a week and 2 weeks of Ceporex ABs as the skin was infected in parts.
November
Itching has stopped, but I notice Doug is loosing a LOT of hair, far more than ever.
The hair on his chest and flanks particularly is very thin.
December
Vets.....heart /lungs healthy, normal temp, anal glands O.K. ears clean and healthy.
Doug is still itchy but skin not infected. Blood taken for allergy testing.......basically because the vets can only offer steroids, and there was a small chance the testing would point to something I could eliminate from his diet

Today
Allergy test results.... Scores between 0 for low-5 for high.
Beef.....3
Lamb....1
All other meats/poultry.....0
Cows milk ....2
White fish/ whole egg/all cereals.....0
Outdoor allergens(pollen)
Beech.....1
Horse Chestnut.....1
All others ....0
Indoor allergens
Storage mites....0
House dust mites....0
Moulds....0
Flea....0
Cat dander.....1 (we have 2 cats )
Sarcoptic mange......negative
Malassezia......4
Staphlococcus.....5
The vet talked me through the results and said there was nothing really that would cause Dougs skin condition.
The malassezia and staph results are high but they are secondary to the skin problem, they are a result of his skin condition not a cause of it.
It was a new vet to the practice that called me with the results and he advised.....
Steroids. I said no, as they work for the length of the course and then it all comes back again.
Continue with the malaseb shampoo twice a week.
Hypo-allergenic prescription food for 3 months then gradually re-introduce his normal food to try and pinpoint what could be causing the itch.
Again I said no. I explained I don't feed processed food, although I didn't actually say RAW! Just said human grade meat.
He was very accomodating and offered to write out an elimination diet for Doug based on the food I feed. I have to wait a few days as he's just joined the practice and all his books are in storage. I'll see what he comes up with!