Thanks for query,
It seems that you might have fungal infection
on the part.
You might have dermatitis
due to some allergy to toilet articles like tissue paper,soap or other things.
You should think of vulvo vaginitis
due to improper hygiene of local part.
Consult gynaec and take her advice,
Apply antifungal or triple action cream locally.
Take some anti histamine
ok and bye.