Psoriasis, commonly known as “psoriasis” and “white H” in Chinese medicine, is a common chronic inflammatory skin disease characterized by erythematous scales. The cause of psoriasis is complex, variable and prone to recurrent attacks. Modern medical research shows that the causes and pathogenesis of psoriasis are related to genetics, infection, metabolic disorders, endocrine disorders, neuropsychiatric factors and immune disorders. In recent years, the incidence of psoriasis has increased significantly, especially among young adults. According to statistics, the epidemiological survey report of psoriasis shows that the prevalence of psoriasis in China is 0.123%. According to the clinical characteristics of psoriasis, it can generally be divided into four types: common, pustular, arthritic and erythrodermic psoriasis. Clinical staging criteria: (1) Progressive phase (progressive phase): new rashes keep appearing, old rashes keep expanding, scales accumulate thickly, inflammation is obvious, surrounded by an inflammatory redness and itching. (2) Quiescent phase (stable phase): the disease is stable, basically no new rash appears, the old rash does not fade. (3) Recovery phase (regression phase): lesions become thinner, inflammatory infiltrates gradually subside, scales decrease, rash shrinks and flattens, leaving a temporary hypopigmented psoriasis white spots, or pigmented spots. Diagnostic criteria for TCM evidence: refer to the Guidelines for Clinical Research on New Chinese Medicines (Zheng Xiaoyu, China Medical Science and Technology Press, May 2002 edition), Chinese Medicine Surgery, refer to the Differential Diagnosis of Chinese Medicine Evidence and the National Standard of the People’s Republic of China? Clinical Diagnostic Terminology in Chinese Medicine”. (1) Blood heat evidence Primary symptoms: the rash is mostly dotted, with new rashes increasing, the original rash expanding, bright red in color, with more layers of scales, intense itching, and dotted bleeding evident when the scales are scraped away. Secondary symptoms: The rash is new or recurring soon, thirsty and drinkable, red and painful throat, or irritable, constipated stool, yellow and red urine. The tongue is red, with thin yellow or slightly greasy coating, and the pulse is slippery or smooth. (2) Blood stasis evidence Primary symptoms: new rash rarely appears, rash is thick and infiltrated, dark red in color, covered with thick and dry white scales, accompanied by varying degrees of itching or no itching. Secondary symptoms: The skin lesions do not subside after a long time, with recurrent attacks, dry mouth and no desire to drink, women may be accompanied by low menstrual flow with dark color or blood clots, dysmenorrhea; purple tongue or petechiae, petechiae, thin white or thin yellow coating, astringent, sunken or slow pulse. (3) Blood dryness: new rash rarely appears, rash is mostly coin-shaped or patchy, light red in color, infiltrated, with reduced scales, dry or with cracking, dry itching or dry pain. Secondary symptoms: longer duration of illness, accompanied by dry mouth and throat, constipation and red urine; light red tongue, thin coating, slow or sunken pulse. (4) Damp-heat evidence Primary symptoms: mostly in the axilla, under the breast, groin and other folds or body flexion, rash is red but not bright, erythema is moist, or oozing, scales are sticky and thick, itching; Secondary symptoms: some patients have the onset related to moisture, and the condition is aggravated by rainy days. It is accompanied by heavy lower extremities, dry mouth and throat without desire to drink, abdominal distension, dull food, fatigue, loose stools or first dry and then loose, and red urine. The woman has a yellowish amount of discharge; the tongue is red with yellow or white greasy coating, or the tongue is fat with teeth marks on the sides. Smooth or slippery pulse. (5) Heat toxicity: Most often seen in patients with acute tonsillitis or upper respiratory tract infection before the onset, especially in children and young people. Most acute onset, bright red lesions, fever, red and swollen throat, swollen tonsils, enlarged local lymph nodes and other general discomfort, dry mouth and bitterness, constipation and urination. The tongue is red and the pulse is counted. (6) Wind-heat evidence: Most of the symptoms are preceded by external sensation, with rapid onset, red color of the base of the skin lesions, accompanied by nasal congestion, cough, runny nose, dry throat, etc. The tongue is red with thin yellow coating, and the pulse is floating. (7) Liver depression: The rash recurrence or aggravation is related to emotional stress or emotional stimulation, and in some women the rash is related to menstruation or pregnancy. The rash is associated with menstrual breast pain, hypochondriacal pain, irritability, insomnia, dry mouth, depression, dizziness, waist pain and other general discomfort, with red or light red tongue and thin or sunken pulse. (8) Yin deficiency: rash is light red in color, less scaling, dry skin, with dry throat and mouth, heat in the hands and feet, tender tongue, little moss or cracks, thin pulse.