None of the diseases are neccessarily life-threatening in time frame considered, but all could alter the comfort and functional level of someone. Yes the fungal infections are "athlete's foot & ringworm", etc.

I suppose (but have no facts to KNOW) that vet meds are actually similar to human meds. I have had patients that self treat with vet meds and seem no worse off for it. I wouldn't recommend that practice. YMMV.