There are two possibilities for this condition: 1, it may be caused by allergy, in the treatment, you can take oral loratadine capsules 1 capsule every night, combined with compound glycyrrhizin capsules 3 times a day, 2 capsules a time to treat. The affected area can be externally applied 2% boric acid solution twice a day, once for 20 minutes, after the application of fusidic acid ointment, and after a few days of crusting, and then externally used Dinocap ointment twice a day, or mometasone furoate ointment once a day to carry out the treatment. During the treatment period, you need to avoid alcohol, spicy and stimulating food, including raw onion, garlic, chili, mustard, and also need to avoid eating beef and mutton, seafood and other hairy things. And to avoid water, so as not to cause local infections occur; 2, consider genital herpes may be greater, mainly due to herpes simplex type 2 viral infection caused by oral vaxilovir hydrochloride granules, external acyclovir ointment for treatment.