I was hoping to get some responses back before answer but I don't want your dog to suffer.
Unfortunately, there are many conditions that can cause a dog to experience hair loss including ringworm, mange, hypothyroidism, cushing disease and allergies. So let me go over those first and then I'll address how to treat mange.
Ringworm can have a scaly reddish rash around the edges of the bare patches though there can be a rash in the bare area as well. Any over the counter antifungal cream for ringworm will work on this. The cream should be applied to an area slightly larger and for about a week after it appears to have cleared up. There are two types of mange and mange is actually caused by mites. Usually hair loss starts in specific areas of the body before spreading to other areas. Allergies are a frequent cause of scratching and hair loss and an be caused by many different things. Treating any problem without knowing for sure what it is causes a delay in the treatment of the real problem if your first guess is wrong. I really suggest you have your Vet examine the areas and diagnose this. Below are websites that will go into more detail on these conditions.
Here is a website on Ringworm:
Here is two on Mange.
Hypothyroidism and cushing on these pages:
You can read up on allergies here:
If you suspect an allergy condition is to blame, you can give your dog Benadryl up to 2mg per pound every 8 hours.
There might be a secondary skin condition in addition to the allergy such as staph dermatitis or yeast dermatitis. Staph usually occurs on the lower regions of your pet and tends to have small pimple type bumps. Shampoo containing Chlorhexiderm and/or Oatmeal can help with this condition though it does not cure the allergy. Yeast typically shows as a greasy area that has a sweet musty odor. Sometimes the skin can become inflamed, darker and thickened due to itching. Yeast likes areas such as between toes, armpits and ears. Selsun Blue Shampoo can help with Yeast dermatitis. When shampooing, lather and leave on 15 minutes before rinsing. These shampoos are not meant to be a cure, just a relief until your pet can see a Vet.
There is also a condition called alopecia which is basically hair loss. You can read all about it in this article:
Some treatment methods for this are discussed on the following site. You might want to discuss this possibility with your vet.
Amitraz Pour On (Mitaban Rx) dip done every other week for 6 to 8 applications or until 2 consecutive skin scrapings is one treatment for mange. Ivermectin is also frequently used to treat mange but should not be used on herding breeds. Some herding breeds are hypersensitive to the drug and it can kill them. You can read about precautions, usage and dosing information here.
And about toxicity here:
Additionally, there is some problems reported with using spinosad (comfortis) with ivermectin so I would check with your vet to be sure you are not using both concurrently.
Some studies have shown that topical application of 2.5% moxidectin–10% imidacloprid is effective against generalized demodectic mange. This might be a good alternative treatment for dogs with a sensitivity to ivermectin or herding breed dogs with the gene mutation causing ivermectin sensitivity. You treat weekly and have skin scrapings and exams done monthly. Treatment continues for one month after 2 consecutive negative scraping and then treatment should be continued once a month to prevent reoccurance if the dog is an older dog with compromised immune system
I've had some success with topical Happy Jack Mange treatment, but I will warn you that it smells like sulfur and stains everything it touches. It is not a good idea to have your dog in the house with this on it. However, I did see hair regrowth in a week with this product. I was also using ivermectin as well.
I hope this information is helpful to you. If you would like any additional information or have more questions please don’t hesitate to press the reply to expert or continue conversation button so I can address any issues you still have . If you do find this helpful, please take this opportunity to rate my answer positively so I am compensated for my time.