Mystery solved (I think)

Josh has been getting a mild rash every couple weeks. It started about 2 weeks after he got diagnosed with scarlatina. The rash hangs out for a week and then starts to fade. We were worried about it for awhile, but think we may have figured it out. He has sensitive skin, and I'm very careful to wash his clothes in unscented soap. However, without thinking, I've been throwing his bedding and towels in with our regular soap for the last couple months. A friend pointed out that it's probably the soap, so now I need to re-wash everything. Oh joy!! Sure wish I had access to a bigger washer and dryer!