Psoriasis is a chronic recurrent inflammatory skin disease of unknown origin, characterized by red inflammatory papules, macules and patches of varying sizes, covered with multiple layers of silvery white scales. Special types may have secondary erythroderma; or fever, pustules; or combined arthritis. The disease is chronic and has a tendency to recur. It is equivalent to the national standard of Chinese medicine disease name “White H”, which is considered to be caused by internal blood heat, blood deficiency, wind and dryness, and loss of skin nourishment. Blood-heat and wind-heat evidence (progressive stage) The main evidence: new rashes appear continuously, mainly papules and maculopapular rashes, the skin at the base of the rash is bright red in color, scraping away the scales to see dotted hemorrhage, there may be isomorphic reaction. It may be accompanied by varying degrees of itching, heartburn, thirst, dry or painful throat, dry stool, yellow urine. The tongue is red, the coating is yellow, and the pulse is smooth or counted. Analysis of the symptoms: the evidence belongs to the blood heat, and then feel the wind-heat evil, resulting in the loss of harmony between the Ying and Wei, Qi and blood, the evil heat congestion blood, so see red spots; blood heat and poisonous evil, injury to the blood and blood deficiency, the skin is not moistened, so see layers of flaking; wind-heat evil and Qi and blood fight knot, so itching; wind-heat dry win, injury to the fluid, so see dry throat or pain, thirst, dry stool, yellow urine; heat disturbing the heart and mind is disturbed heart. The red tongue with yellow coating and slippery pulse or number are signs of wind-heat and blood-heat. Blood deficiency and wind dryness (quiescent phase or receding phase) Main symptoms: prolonged illness, rash is mainly patchy, with lighter skin color at the base of the rash and more but thinner scales. There may be itching, fatigue, dry stool and dry mouth. Pale red tongue, thin white coating and thin pulse are signs of blood and fluid deficiency. Blood stasis and vascular evidence (quiescent or receding stage) Main symptoms: long duration of disease, thick infiltration of skin lesions, dark red skin at the base of the rash, tight scales. The lesions are limited and do not fade. There may be varying degrees of pruritus. Systemic symptoms are not obvious. The tongue is dark red or with petechiae, and the pulse is astringent or fine. Analysis of the symptoms: The evidence belongs to the long-standing disease meridian blockage, Qi and blood stagnation, skin loss of nourishment, so see the infiltration of skin lesions, thick, solid flakes; blood blocking the channels and veins, Qi and blood flow is not smooth, so the rash color is dark. Dark red tongue or petechiae, astringent pulse or fine astringency are signs of internal blockage of blood. Cold-damp paralysis and obstruction (arthrosis type) Main symptoms: lighter skin color at the base of the rash, thicker white scales, light itching. Painful swollen joints, reduced to deformed joints and impaired movement, aggravated by cold and relieved by heat. The mouth is light and not thirsty. Pale tongue, white coating, smooth pulse. Analysis of the symptoms: The evidence is a mixture of wind, cold and dampness, paralysis of the meridians and channels, blockage of Qi and blood, and pain if it does not pass, so the joint is swollen and painful; the tendons and joints lose nourishment over time, so the joints are deformed and activity is impaired; heat is more fluid Qi and blood, so the pain is reduced; when cold, the blood is easy to coagulate, so the pain is more intense; wind, cold and dampness are external congestion of the skin, so the color of the lesions is light, itching is light; cold is a yin evil, does not hurt the fluids, so the mouth is light and not thirsty, the tongue is light, the fur is white, the pulse is smooth. Slippery is the sign of cold and damp internal obstruction.