Talk to Dermatologist on Skin Rash From Sanitary Napkin

I got my 1st ever sanitary pad rash 3 months ago ..... On my iner thighs there are small raised blisters without any fluid and severe itching.. I used hydrocortisone cream it worked somehow But now the rash is again flaring up Kindly suggest me some cream along with systemic medicine that I can use I will have my next cycle in 10 days and it's a night mare for me