What is the incidence of psoriasis? The prevalence of psoriasis fluctuates between 0.1% and 3.0% in the natural population, with more Caucasians, followed by yellow people, and less black people. The highest is among the inhabitants of Faroe Island in Denmark, which has almost become the “home of psoriasis”, while the Indians in South America are basically free of the disease. In the 1984 national epidemiological survey of psoriasis, the prevalence rate in China was estimated at 0.123%, with more than 2.5 million psoriasis patients nationwide. The prevalence of psoriasis is higher in men than in women, in urban areas than in rural areas, and in the north than in the south. At what age does psoriasis tend to occur? About 80% of psoriasis first occurs in young and strong people with strong qi and blood, mostly aged 15 to 45 years old, with the peak age of onset at 20 years old and the average age of onset at 28 years old for men and 24.6 years old for women, with a common family history, called early onset; a small number of psoriasis patients have the peak age of onset at 60 years old, with a rare family history, called late onset. What season is psoriasis prone to develop? Clinical studies have concluded that the onset of psoriasis has a certain relationship with the seasons. Most people have the winter type, with the onset of psoriasis aggravated in winter and the lesions reduced or disappeared in summer when the climate becomes warmer; a few patients have the summer type, with the lesions aggravated or recurring in summer and reduced or receding in winter when it is cold. In some chronic patients, the seasonal changes are no longer obvious due to lingering disease or improper treatment. What are the causes of psoriasis? The onset of psoriasis is controlled by multiple genes and is also influenced by environmental factors such as lifestyle, economic conditions and dietary habits. Psoriasis has a genetic predisposition, and the mode of inheritance may be polygenic. Infections, mental and neurological factors, smoking and alcoholism, local trauma, drugs, and endocrine changes are also contributing factors to psoriasis. What should be paid attention to especially for patients with progressive psoriasis? Not only trauma, other inappropriate stimuli: mechanical injuries, such as surgery, needles, scratching, friction, mosquito bites; physical injuries, such as freezing, burns and exposure to sunlight, ultraviolet rays, radiation; application of certain drugs, such as lithium, beta-blockers (insulin) anti-syndrome drugs, some non-steroidal antibiotics (anti-inflammatory pain), interferon and interleukin-2, and the combination of certain skin diseases such as This phenomenon is known as “isomorphic reaction”, which occurs in the acute and active phases of psoriasis. Therefore, it is necessary to avoid all kinds of adverse physical and chemical stimuli, use internal and external drugs of Chinese and Western medicine cautiously, treat them carefully and actively Therefore, it is necessary to avoid all kinds of adverse physical and chemical stimuli, use internal and external medications of Chinese and Western medicine cautiously, treat them carefully and treat them actively. Is psoriasis contagious? Scientific research has confirmed that psoriasis itself is not contagious. No one has been able to culture fungi or detect the presence of bacteria on psoriasis skin lesions. Many families where parents and siblings have successive illnesses are due to genetic factors and are in no way contagious. Patients and their relatives, colleagues and friends should understand that although psoriasis patients’ skin lesions are unsightly, they are definitely not contagious. The public should understand psoriasis patients and create a harmonious atmosphere, which is conducive to patients adjusting their mindset and interacting normally with society, which is of great benefit to the early recovery of psoriasis patients. How is psoriasis clinically typed and what is the correlation between them? Psoriasis is generally clinically divided into four types: common, erythrodermic, pustular and arthritic. Psoriasis vulgaris is the most common, relatively mild and stable. However, when stimulated by infection, hypocalcemia, psychological factors, sunlight and various drugs, biological and physical and chemical factors, common psoriasis can be transformed into erythrodermic or pustular psoriasis. After receiving effective treatment, erythrodermic or pustular psoriasis can be transformed into common psoriasis and then gradually fade away.