skin condition

I have a siberian husky who has had every diagnosis in the dictionary.  She is a beautiful dog....nonetheless her recent condition worries and I feel that the doctor might have misdiagnosed.  About two months ago I noticed a difference in her skin texture.  After a thorough pup rub, I noticed that she these "scabs"  all over.  We went to the vet and he put her on antibiotics.  They went away.  Well I noticed over the last week on her lower back above her back hips the "scabbing" is back and is really bad in that area.  I know she needs to go back to the vet to have this looked at but I am waiting for husband to check her out first.  Today we were at the field and I was rubbing her down and noticed that her hair easily falls out in large chunks.  I know exactly what the vet is going to do....I would really like some advise so I can go into the vet with questions and an idea of what she could possibly have or even mention options if the vet ignores what it possibly could be.  She is on hypoallergenic food and we only use hypoallergenic bathing soap.  She does not eat table food....besides peaches and asparagus and carrot juice...which the vet already approved.....I don't know what to do...Advise?

[Kimberly Coyner, D.V.M., DACVD]

Crusts and hairloss typically indicate an infection of the hair follicles, most commonly a bacterial infection, which is treated with antibiotics for at least 21 days and weekly mild antibacterial shampoos. If antibiotics are not given for a sufficient duration, the infection will recur within 1-2 weeks. Fungal skin infection (ringworm) and microscopic demodex mites (mange) can also cause similar symptoms, but would not usually respond to antibiotics alone. When I am faced with a case as you describe, I first take skin scrapings for microscopic analysis for bacteria and mites. If no organisms are seen, I then perform a fungal (ringworm) culture. If all I see is bacteria I treat with antibiotic, but if infection resolves completely and then recurs, we have to find the underlying cause. In an otherwise young healthy dog the most common underlying cause would be a hypersensitivity or allergy to fleas, food, or pollen/dust. She should be on a good monthly flea control such as Frontline, Advantage, or Revolution. Additionally even though you state she is on a "hypoallergenic diet" this does not mean she could not have an allergy to a component of the food--hypoallergenic means a diet with one protein and one carbohydrate source that the immune system has never been exposed to before. So even if she has been long term on a fish/potato or lamb, duck,or venison based diet she can develop an allergic response to those ingredients, and with the recurrent skin infection a different hypoallergenic diet may be needed  (as an aside, this is one reason that I do not advocate novel ingredient diets for normal, non-food allergic dogs, because if they end up eventually developing an allergy to the novel protein, then its harder to find something even more different to change to).
Hope that is helpful, good luck,
Kimberly Coyner DVM DACVD
www.dermvet.com