If there is a small lump on the vulva and it is painful with localized redness and swelling, the most common cause is caused by small boils on the vulva, which is acute inflammation caused by bacterial infection on the vulva. The most common cause is a small boil on the vulva, which is an acute inflammation caused by bacterial infection of the vulva. Therefore, after the formation of localized redness, swelling, heat and pain, it is recommended that the localized area can be washed with water or red nuclear wash, and then applied with Pepto-Bismol. If Bactrim is allergic, erythromycin ointment can be applied for treatment. It is recommended not to have sex during the treatment period, not to eat acidic and spicy food, and it is recommended to wear cotton loose underwear to avoid friction, so it is also recommended to keep the vulva locally clean in daily life. If after the above treatment, the symptoms are not reduced obviously, you can also take oral antibiotics for treatment, if there is no drug allergy, it is recommended to take oral metronidazole for treatment.