Psoriasis, commonly known as “psoriasis”, is a common, recurring, chronic inflammatory skin disease with characteristic lesions. The main symptoms are red papules or plaques covered with multiple layers of silvery white scales, and in addition to erythema, papules and scales, there can also be blisters, pustules and other lesions, more often on the extensor surfaces of the limbs, scalp and lumbosacral area, but also involving nails and joints, and some patients have itching. How to self-diagnose common psoriasis? If there are red plaques above the skin surface covered with multiple layers of scales, which are usually found on the extensor surfaces of the limbs, scalp and lumbosacral area, heavy in winter and light in summer, it can be highly suspected. The etiology of psoriasis The etiology of psoriasis is not yet fully understood. It is an autoimmune disease mediated by T lymphocytes in a polygenic genetic background and is induced or aggravated by internal and external environmental factors such as trauma, infection, drugs, combined diseases, diet, smoking and mental trauma. 1, genetic factors: psoriasis is polygenic inheritance. 2, obesity and overweight: a study found that the obesity rate of patients with psoriasis vulgaris is higher than that of the general population, and the severity of the disease is related to the body mass index. 3, infection: infection is one of the triggering factors for the onset, recurrence or aggravation of psoriasis. 4, drugs: some drugs can trigger the onset and aggravation of psoriasis, common treatment of hypertension and heart disease beta-blockers, angiotensin converting enzyme inhibitors, etc. 5, other: alcohol and smoking increase the risk of psoriasis and are associated with the aggravation of psoriasis. What are the dangers of psoriasis? Although psoriasis is a systemic disease, the main symptoms are manifested in the skin, and proper treatment does not affect health in general, without damage to internal organs. There are some special cases that have certain effects on the whole body, such as: arthritic psoriasis, erythrodermic psoriasis and pustular psoriasis, which are accompanied by fever, general malaise, electrolyte disorders, hypoproteinemia and heart dysfunction. The serious harm caused by psoriasis to the body is often related to irregular treatment or long-term lack of effective control. Patients’ long-term psychological stress complicates cardiovascular diseases, metabolic syndrome, malignant tumors and other major diseases. Therefore, standardized treatment, effective treatment, control of relapse, improvement of quality of life and prevention of complications have become the currently accepted treatment strategies.