My grandson, aged 22 months, has a very severe diaper rash. He often gets a rash when teething but this time is the worst. Dr. prescribed a steroid plus anti fungal cream on Wed eve, but 2 days later and the rash appears to be spreading upwards from the anal area to his penis. Does this mean the cream is not working ? Should his diet be altered until it is fully cleared up ? ie, should we cut out yeasts, yogurts and baby Liga biscuits.