Based on the images you uploaded, a fungal infection
is likely. If the diagnosis is in doubt then scraping test should be performed to confirm it.
Initially topical antifungal
such as clotrimazole
are advised. If the lesions do not resolve with topical treatment then oral antifungal
drugs such as terbinagine can be considered for treatment.
The adverse effects which you described are not usually scene with antifungal treatment specially topical preparations.
For quicker resolution adding a zinc supplement
can also help. Keep the area dry and for superimposed bacterial infections in the areas which are cracked/ open wounds, topical antibiotics like gentamicin should also be applied.
Wishing you best of health