Atopic Dermatitis Shampoo suggestions

Jesse continues to have issues with the above. We have been using Virbac Kertolux shampoo but it appears Virbac is no longer doing business in the US. Thoughts on other shampoos? We had him at about 95% clear but the extended heat and humidity we've been experiencing sent him backwards. He is also taking ketoconazole but our vet is concerned with him staying on it too much longer. I have seen some shampoos with keto in it. Is topical application as effective as oral form? Comments/suggestions welcome.