Ummm, you've had these guys 2&1/2 or 3 weeks. I don't think humidity is the problem. But maybe the paper towels. Paper products should be unbleached, as I've heard of fish getting a diease from using cotton in a biologic filter. I think people use the paper to make sure additions are eating(pooping) and to easier gather fecal samples. The dust that comes off white paper towels is much greater than what comes off of brown ones. I've also read red leg looking irritation can come from cardboard or paper towel.

Just my guess.

Try posting a picture of the temporary home