Skin cracking a crack, may be atrophic lines, ichthyosis, lack of fat eczema, etc.. 1. Atrophic lines: relatively rapid weight gain and rapid changes in height may lead to mechanical overstretching of the skin and breakage of subcutaneous elastic fibers, and the surface of the skin may appear reddish and whitish striped lesions. 2. Ichthyosis: the cause of ichthyosis is mainly related to heredity. If one of the parents has ichthyosis, their children may develop ichthyosis under the influence of genetic factors. The main manifestation is dry skin, ichthyosiform lesions, which look like cracks. 3. Lack of sebum eczema: also called winter itch and cracked eczema, it is considered to be related to the cracks that appear on the skin due to excessive loss of skin moisture and reduced sebum secretion caused by various factors. If cracks appear on the skin, it is recommended to go to the hospital to clarify the cause of the disease.