Scales are thin flakes of epidermal keratin layer that are about to be shed or have been shed. Its size, shape, thickness, quantity and color vary, some are dry, some are greasy; most of them are secondary damages of skin diseases with erythema or papule damage (such as psoriasis, seborrheic dermatitis, pityriasis rosea). In the palm of the hand with thicker stratum corneum, the foot staggers with a hyaline layer between the granular layer and the stratum corneum, and the epidermal keratinocyte growth and metabolic cycle is 12 days under normal conditions. A prevention of infection Local infection is an important cause of psoriasis, especially after the flu, complicated by tonsillitis bronchitis, need to be actively treated to minimize the course of the disease repeated inflammation of the tonsils, closely related to psoriasis attacks, tonsillectomy can be considered this is particularly important for adolescent patients. Two allergic factors is one of the important triggering causes of psoriasis. Allergies due to diet or medication, or contact with a substance can often trigger the occurrence of psoriasis. After each relapse, patients need to carefully recall what they have taken or touched a certain substance in the recent past, which makes the skin itchy, followed by the appearance of red spots. For example, certain seafood, beef and mutton, spicy things and other substances, etc. The number of psoriasis induced by wind and cold is high, because the damp living environment and cold weather can make the disease occur or aggravate, so patients should try to avoid large cold and heat to stimulate the skin, and keep the living room ventilated and dry. Four mental factors Daily life due to work pressure, rest is not good, excessive mental tension caused by emotional instability, worry and depression, and can not reasonably adjust the maintenance of skin or long-term diet is not regular overeating, eating fishy and windy things, excessive alcohol and tea and external causes caused by cold, fever, tonsillitis immune function is low, lack of resistance, which leads to the onset and recurrence of psoriasis excessive Mental tension, anxious temperament, emotional depression and other mental factors are the first of other triggers, accounting for about 18.6% of the total incidence of psoriasis in China. Excessive mental tension can produce a series of psychological or physiological reactions, prompting neuroendocrine disorders, damaging the body’s immune defense system and metabolic disorders of certain enzymes, thus promoting the occurrence of psoriasis. Therefore, in the event of irresistible or unpredictable unexpected things patients should try to control their emotions, maintain a calm mood and ensure sufficient sleep time. Five careful use of the following controlled drugs What kind of drugs are chosen for the first time to treat psoriasis plays a key role in its efficacy and whether it recurs after healing. During a period of time, the medical profession has, to a considerable extent, walked into a misunderstanding on the direction of research on the treatment of psoriasis. The main manifestation is that when papular erythema first appears on the body of psoriasis patients, it means that the immune ability of the patient’s body is reduced, the endocrine function is disturbed and the microcirculation is not smooth, resulting in the skin excretion dysfunction so that the endotoxin that should be excreted in the body accumulates under the skin. The drugs used are not used to improve the immune system and restore the normal metabolic function of the skin to excrete endotoxins, but hormones and immunosuppressants are used to suppress the immune control of the excretory function of the skin, resulting in heavier and heavier treatment, eventually causing the condition to become more stubborn and difficult to treat.