I was experiencing chronic itching in my bikini area a few months ago. I went to the doctor and there was no infection found. My doctor then suggested that I switch to a hypoallergenic laundry detergent. I did but the trouble continued. I finally started to suspect my panty liners. They were perfumed and I realized that I might be allergic to the perfume. I stopped using them and the chronic itching disappeared. Apparently, any kind of personal hygiene product and even underwear itself can cause allergic reactions and chronic itching.
I now wear 100% cotton underwear with non-perfumed panty liners and I also use perfume free laundry detergent. I just want to warn other women who may face the same problem.