The Chinese medicine identification of allergic purpura is divided into four categories through the dialectical treatment of Chinese medicine theoretical system, as follows: 1, heat poisoning spot evidence: the treatment is to clear heat and cool blood, eliminate spots and spots, the formula is Rhizoma Dihuang Tang plus or minus; 2, wind-heat injury to yin evidence: the treatment is to remove wind, clear heat, cool blood and stop bleeding, the formula is Yin Qiao San plus or minus; 3, yin deficiency fire evidence: the treatment is to nourish yin and clear heat, cool blood and eliminate spots, the formula is Zhi Bai Dihuang Tang and Da Yin Wan; 4, spleen qi deficiency evidence: the treatment is to nourish qi, take in blood, harmonize the middle and strengthen the spleen, the formula is Gui Shen Tang plus or minus.