It is possible that your dog has a skin infection, ringworm (a fungus), or maybe mange.
Skin infections can look like circular areas with scabs or peeling fur around the edges, may be itchy, and the skin can look red. Oftentimes skin infections are on the lower belly and inside of the back legs, but they can show up anywhere, especially in skin folds. You will need antibiotics for a skin infection.
Ringworm usually is more localized, but can spread. It also looks like a round, scaly area and tends to be itchy. Ringworm requires a special antifungal medication given orally, if it is in more than one or two places. Your vet will likely shine a Wood's light on the area (some ringworm fluoresces green) and take a hair sample to see if the fungus grows.
Finally, sarcoptic mange can show up as scaly or scabby areas, particularly in the armpits, around the ears or on the face, then spreading around the body. It tends to be VERY itchy and can develop a secondary infection. It requires treatment with something like ivermectin, although there are other medications that your vet may prefer. Sarcoptes can be difficult to diagnose as it is hard to find the mites. Sometime the vet will just treat for it.
Demodectic mange is less common, particularly in adult dogs. It will be a scaly spot on the body and isn't usually itchy. Your vet can diagnose demodex with a skin scrape.
So take your dog to your vet soon and find out how best to treat her!