Hi
Rashes during periods can be due to multiple causes like friction, contact dermatitis, heat, moisture or infection.
Some of the tips includes
Frequent changing of pads, try switching to another brand in case of allergic reaction, choose the size according to your flow, use of tampons or mentrual cup.
In case of vaginal itching or discharge consult a dermatologist for treatment of infection.
Health Tips
try keeping the area dry and wear cotton undergarments.