There are many types of hereditary ichthyosis, the most common being common ichthyosis and sex-linked ichthyosis, which have a high incidence. The prevalence of common ichthyosis may be around 5-10% in China, while sex-linked ichthyosis is a few thousand to one. Common ichthyosis is semi-dominantly inherited, normal people have two disease-causing genes, and the disease may develop if one of them is faulty, and the disease will be more serious if the other gene is also faulty. Sex-linked ichthyosis is sex-linked and is an X-linked recessive mode of inheritance. Usually, men have the disease and women are only carriers and will not develop the disease; however, if they are carriers, there is a 50% chance that their offspring will have sex-linked ichthyosis if they are sons. There are also some rare recessive ichthyosis, which are grouped into a type called autosomal recessive congenital ichthyosis, and the typing of this inheritance pattern is very important to determine whether the offspring or other members of the family have the disease. Of course, there are very many subtypes within each type, and we only need to know that there are four types: autosomal dominant, autosomal recessive, common ichthyosis and sex-linked ichthyosis. The four ichthyosis subtypes have different incidence rates for family members, offspring, and the probability of risk of reoccurring disease. For example, in the case of autosomal recessive ichthyosis, both husband and wife do not have the disease, but the child is ichthyosis, and it is more severe. In this case, if we can determine that it is autosomal recessive congenital ichthyosis by some means of examination, we can determine that the probability of this couple having another child with the possibility of having a similar condition again is 25%. In contrast, if his child finds a normal person to marry and have a child, generally the offspring is a carrier and will not exhibit the disease. The other three diseases also need to be judged according to different inheritance patterns before making a judgment based on the patient’s family situation. The incidence of common ichthyosis is very high, and it is entirely possible for a situation to arise where both husband and wife have very mild common ichthyosis and are unaware of it themselves. In fact, many people have mild ichthyosis, for example, in winter, the skin on the calves and arms is rougher, with some polygonal scales, and a little white skin will fall off when taking off autumn pants; the palm lines are particularly coarse and messy, with deep grooves, and there are chicken skin-like bumps on the arms, which are particularly rough to touch, this may be a milder form of common ichthyosis, which belongs to the FLG causative gene carrier. This gene has a high probability of being carried in normal people, and it is possible for both husband and wife to carry it at the same time, and their offspring may have recessive ichthyosis vulgaris, which is more severe than both of them. In this case, the child will have more scaly calves, palm lines and periorbital keratosis than both parents, and the scaling will be more extensive. Sex-linked ichthyosis usually develops only in males, and the offspring of a male patient will be carriers of the disease if they are daughters, but not if they are boys. It is unlikely that both parents have recessive ichthyosis, because the onset of recessive ichthyosis is both severe and rare, and it is unlikely that both parents will have children in combination. However, if both parents have severe recessive ichthyosis, the offspring must have this disease and it will be very serious. From the current scientific means, we have no way to avoid the development of children carrying this disease-causing gene. However, ichthyosis may have some adverse prognosis, or complications, such as eyelid ectropion leading to corneal damage, or mouth and lip ectropion, affecting teeth or oral health, and finger contracture. If we can diagnose early and intervene in advance, we may not have such serious consequences. We can only improve and alleviate the many symptoms brought about by the disease, so that the patient can obtain a better quality of life and live an ordinary life as much as possible, which is the goal of our treatment.