Bumps , lumps, rashes that come and go, and especially weird rashes could be Bartonella.
Lyme erythema-migrans can also come in go in some people. I had that happen many times after my Epsom salt baths.
Here is some info:
jemsekspecialty.com/erythema-migrans/also ringworm images and info:
/www.medicinenet.com/ringworm/article.htm#what_does_the_term_%3Cem%3Eringworm%3C/em%3E_mean