Summary of case history,　A 58-year-old woman presented with repeated polyarticular pain for more than 5 years, with an exacerbation of recurrence of 1 week. The patient always likes to eat rich and delicious foods. More than 5 years ago, the patient had no obvious cause for the pain in the interphalangeal joints and knees of the right middle finger. The skin temperature was not high, the skin color was not red, there was no morning stiffness, and there was no obvious limitation on joint movement. After seeing a doctor in an external hospital for infusion and drugs, the symptoms eased slightly, causing no attention and no systematic treatment. Since then, the condition has repeatedly, especially when the weather changed and the patient was tired. A week ago, there was no obvious inducement for the occurrence of pustules in both lower limbs with pain and pruritus, and the ulcers were formed after the blister wall was ruptured due to unbearable hand scratching. The ulcers leaked with yellowish liquid. On May 25, 2020, I visited Professor Long Yunguang and recognized it as the damp-heat stasis syndrome of Sanghudie sore. The treatment was based on the methods of clearing heat, eliminating dampness, activating blood, and resolving stasis. The ulcers in both lower limbs were significantly improved after treatment with the proposed five-ingredient disinfection decoction combined with the addition and subtraction of Qinghao Biejia Decoction.,TCM diagnosis,　red butterfly sore; hot and humid blockage certificate,Western medicine diagnosis,　systemic lupus erythematosus,Therapeutic methods,　Wuwei Xiaodu Decoction combined with Qinghao Biejia Decoction took 72 doses.,Clinical outcomes,　The ulcer of both lower limbs improved obviously.