Could a spreading yeast infection end up all over the body and cause meningitis?

Canidda. It depends on where the yeast infection occurs - while it can cause meningitis it usually has to get into the blood stream and if the individual is otherwise healthy with no immunosuppression yeast infections do not typically cause meningitis.
Wouldn't plan on it. Yeast meningitis is generally a problem for the severely compromised patients who end up in an ICU & have very poor or no immune system function. We have yeast in our digestive tract at all times & it gets on our skin & membranes constantly. The immune system and intact skin/membranes keep it out of the blood which is where it must go to get to the meninges. I wouldn't worry about a rash doing it.