Somtam skin problem, vet visit

Somtam started scratching his back last month, like he got itchy all the time. At first I thought it was just dust in the cage, so I changed the bedding. Then little bald patches appeared on his side and the skin was red and flaky. I got scared so I brought him to the exotic vet in Ari. The vet checked him with a lamp and said it is probably a fungal infection with some mites. Not too serious but he needs cream for 3 weeks and to clean the cage every day. She also told me to check Mook for the same thing because they sleep in the same room. Mook is fine, but I had to give her a bath with a special shampoo to be sure. She hated it lol. Total cost was about 1,800 baht with the cream and the test. Cheaper than I expect actually, but the cream smells strong and Somtam makes a face every time I put it on. He is much better after 2 weeks, hair growing back. I think the biggest problem was I used cloth bedding that did not dry well after wash. Now I use paper bedding and wash everything in hot water. My mom says I am too much but the vet agrees with me. If your guinea pig scratches a lot please dont wait, they can get sick very quickly. Ask your vet about the cause and the cage cleaning routine. Also I want to say thank you to the vet nurse who held Somtam so nicely during the test, he was not shaking at all.