Guinea pig skin problems

Question
I got my guinea pig around 3 weeks ago, and when I bought him he was perfectly fine. He was fine also for about the first week, but then he started to lose hair between and under his eyes. I thought it was mites, but that's the only place it is. They are dark scabs. He eats fine, and runs around like normal, just spends a lot of time in the igloo I got him. I think it may be a fungus. But how does a guinea pig get a fungal infection? He hasn't been around outside or anything. I keep his cage clean too. I fed him oranges because it was high in vitamin c, but i stopped because of all the acid in it and I read on here that acid will do that. I stopped feeding him oranges a little over a week ago, and its still not going away. Please help me! I don't have money for the expensive vet bill. I thought about wiping it with a baby wipe and putting bag balm on it, is that bad?

Answer
well mange is still a possiility, though fungal is more likly so your instinct i would say is right, nd oranges dont tend to make somthing as severe as you decribe. guinea pigs can get it the same way as humans. antiiotics are the best treatment, have a looks around your local pet shops and pharmacy's see if anywhere they sell baytril, this is a piggy freindly antibiotics, id say two weeks on this and he should be fine