1. How many types of ichthyosis can be classified and what are the common symptoms? At present, according to the pathogenesis of ichthyosis, especially the genetic mechanism, ichthyosis can be divided into more than ten types, all of which are characterized by dry skin and ichthyosquamous scales, and the specific performance varies among different types of diseases. Usually, the ichthyosis we refer to is called common type ichthyosis, which is the most common type, mainly manifested as dry skin since childhood, with large scales all over the body (similar to fish scales, hence the name), especially on the back of the hands and extensor side of the extremities. 2. Is the incidence of the disease high and at what age does it occur? Ichthyosis vulgaris is a common disease, and the prevalence rate is estimated to be about 4 per 1,000 in foreign countries. It usually does not develop at birth, but starts to appear at a few months and gradually worsens, and is most severe around 2 years of age, but then gradually decreases. 3. What is the cause of ichthyosis and is the disease contagious? At present, it is believed that ichthyosis vulgaris is a hereditary disease, which may be related to the mutation of FLG gene in chromosome, causing the reduction of filament polymeric protein in the skin, which is an important substance to maintain the integrity of the skin including keeping the moisture of the skin, and it can produce natural moisturizing factor and other components after metabolizing, causing the corresponding clinical symptoms. Therefore, the disease is not contagious. 4. Is ichthyosis hereditary, and is the probability of the child getting the disease greatly increased if one of the parents has the disease? Ichthyosis vulgaris is a complex genetic disease, and the probability of children with one parent suffering from the disease is significantly higher than that of healthy people. 5. Can ichthyosis damage other organs? Since the lesions of ichthyosis vulgaris are on the skin, there is no direct damage to the heart, lungs, liver and kidneys, but patients have a significantly higher rate of allergic rhinitis and asthma. 6. Can this disease be cured? Given that ichthyosis vulgaris is a genetic disease and the patient’s own genes are defective, it cannot be cured at present, but through treatment and care, it can significantly relieve the symptoms and improve the quality of life.