Patient male, 25 years old, first seen on September 15, 2011. Complaint: erythema, papules and herpes with pruritus on both lower extremities for 5 days. Itching is obvious, vesicles and blood crusts are visible due to scratching, oozing fluid is visible on the vesicle surface, irritability and thirst, dry stool and red urine, dark red tongue with yellow greasy coating, smooth pulse. Traditional Chinese medicine diagnosis: damp sore, Western medicine diagnosis: acute eczema. The diagnosis of TCM is damp-heat infiltration, treatment is to clear heat and cool blood to relieve dampness. Prescription: Dioscorea Z10g, Phellodendron Bark 15g, Phellodendron Bark 12g, Tu Fu Ling 15g, Niubizi 12g, Ze Xie 10g, Sheng Cai 25g, Bitter Ginseng 12g, Bai Xian Pi 15g, Dandelion 15g, Dan Pi 8g, Sheng Di 10g, Red Peony 10g, Licorice 5g, decoction in water, 1 dose daily, divided into 2 doses in the morning and evening, for 7 doses. Externally, apply 10% Phellodendron solution as a wet compress twice a day for fifteen minutes each time. Second consultation: the vesicular surface was healed after medication, itching was obviously reduced, rash gradually faded, rash color became lighter, less nausea, loose stool, abdominal distension, followed by the above plus Atractylodes macrocephala, Atractylodes macrocephala, Houpa with 15g each, 14 doses in a row. Third diagnosis: the patient’s skin lesions on both lower limbs basically disappeared, leaving temporary pigmentation spots. Followed by adding 20g of Salvia miltiorrhiza above, and then 7 doses to consolidate the efficacy, and advised him to avoid diet. Follow up six months without recurrence. Press release: eczema is a kind of allergic, inflammatory skin disease with obvious tendency to exudate; clinical manifestations for polymorphic damage, symmetrical distribution, itching vesicles, flow of nuisance crust, recurrent, easy to evolve into chronic. In the “Golden Guide to Medicine”, it is said that “sores are found all over the body, shaped like corn, itching without measure, and when scratched, they are soaked with fat and water and become flaky”. Yang believes that this disease occurs from the outside but actually occurs from the inside, with dampness and heat fighting each other in the body, unable to ventilate the outside and unable to guide the inside, and caused by flooding the skin couples. In this case, erythema, papules and herpes on both lower extremities, after scratching the vesicular surface and oozing fluid are identified as damp-heat infiltration, which goes outside the skin; the tongue is red with yellow greasy coating, and the pulse is smooth and slippery, which is a sign of damp-heat accumulation. The four diagnoses of Yang’s teacher were combined with the reference, so he prescribed Dioscorea Z Dampness Infiltration Soup plus or minus. In the formula, Huang Bai, Dandelion, Tu Fu Ling, White Flower Snake Tongue Herb cleared heat and detoxified dampness; Dioscorea Z, Ze Xie, Raw Job’s Tears lightly permeated dampness, and all the medicines were used to guide the evil to go from the stool, to drive away the evil must give the evil a retreat, and to take advantage of the situation to win; Dan Pi, Sheng Di, Red Peony nourished Yin, cooled blood and invigorated blood, all three medicines entered the blood, so that the evil in the blood was cleared, and the Ying and Wei Qi and blood were harmonized to promote the healing of the disease; Bitter Ginseng, White Fresh Peel cleared heat, dampness and relieved itching; Niubizi The bitter ginseng and Bai Xian Pi clear heat, dry dampness and relieve itching; Niu Knee leads all medicines downward. The “good doctor does not waste external treatment” chose Huang Bai liquid for wet application, and used both inside and outside. After the use of the medicine, the evil potential has been folded, see the evidence of spleen deficiency and dampness stagnation, so the addition of Atractylodes macrocephala hard warm dry dampness to strengthen the spleen; Atractylodes macrocephala beneficial qi to strengthen the spleen to cut off the source of dampness; thick park hard warm dry dampness to move qi to remove fullness. In the third diagnosis, only pigmentation was added as appropriate to follow up. Dr. Yang examined the condition in detail and issued the medicine, and the prescription hit the disease mechanism, with promising results.