clinical manifestations of this disease include excessive palmoplantar keratinization, the palmar or plantar become yellow divergently with around the edges or abnormally excessive sweating and clinical manifestation appear in a symmetrical form on the body. Hereditary benign intraepithelial dyskeratosis Hereditary benign intraepithelial dyskeratosis is a rare type of genodermatosis that may occur in infancy and early childhood, its symptoms often appear in the patients' eyes and mouths. The patients' eyes appear red due to the dilatation of superficial vessels and appearance of conjunctival plaques in their eyes, patients may have variable-size, thick, soft and white plaques in their mouth. Spring is an acute episode of symptoms, such as itching, erythema, photophobia and so on. Epidermolytic hyperkeratosis Epidermolytic hyperkeratosis is a rare genodermatosis which is also referred to as disorder of cornification type 3 and bullous congenital ichthyosiform erthroderma, affecting almost 1 per 200,000 - 300,000 people. They also stated that its clinical manifestations often begin at birth with large rashes all over the body, and the patients' skin will be so sensitive that even mild wounds can cause blisters and peeling. Potential complications of this disease include electrolyte disturbances, sepsis and so on. Hidrotic ectodermal dysplasia Hidrotic ectodermal dysplasia is a rare genodermatosis which is also known as Clouston syndrome. The patients' nails may be too thick, too brittle, too bent or have different colors, their hair also appear mottled, sparse and other abnormalities. These symptoms often begin when the patient is an infant. Diagnostic methods Genodermatosis is often rare and varied, but diagnostic methods have some commonalities, the diagnosis of rare genodermatosis is basically divided into six steps: 1. Each genodermatosis has different clinical manifestations. People can observe the special features and changes of the skin to judge whether they are sick or not. Features will be different in different age groups, so it is necessary to observe and record the special features of the skin in each age group; 2. Genodermatosis is a hereditary disease, knowing as much as possible about a detailed and complete family history helps in screening and diagnosis; 3. People can do a detailed physical examination to observe the special features and manifestations of other organs besides skin. It can help to narrow down the disease and make a definitive diagnosis; 4. People can carry out laboratory tests such as skin biopsies with high-tech and precise scientific instruments to have further results; 5. Different