One possible cause of an itchy, red rash between your toes is athletes foot. However, to conretly determine what the cause is, you should schedule an appointment with your doctor.
If you wear bad quality shoes and your feet sweat a lot, get ready for a red rash as well. But there is solution. Use special feet talk powder (you can buy it in many specialised stores)and wear leather shoes only and red rash will be past for sure! Good luck!