After long time walking,friction of thighs might lead to damage to hair follicles.
And that may be followed by follicultis.
So I feel you may be having follicultis.
Along with that,you may be having candidal infection, and that may be due to perspiration.
Avoid soap bath, use dettol
liquid for bath.
Keep the area dry.
Take antibiotics for few weeks.
Antifungal tab like ketoconazole
may be taken.
If there is itching, take antihistaminic.
Apply antibiotic and antifungal creams.
You should take rest for few days.
However, you may consult dermatologist
I hope you got my answer.
Dr. Ilyas Patel MD