There are many possibilities: 1) folliculitis, caused by subcutaneous bacterial infection; 2) boils, caused by local skin infection after scratching due to inattention to perineal hygiene; 3) genital herpes caused by viral infection; 4) local allergic symptoms caused by repeated rubbing and irritation of vulvar skin by poor quality underwear or hygiene products. If there is no obvious redness, swelling or pain, it is recommended to wash and change underwear regularly, wash the vulva with water, avoid scratching and keep the perineum dry and clean. If there is itching, redness, swelling and pain, it is recommended to consult a specialist and use anti-inflammatory drugs or topical lotions under the guidance of a physician.