Lichen planus, also known as recessive congenital ichthyosis vulgaris, is a rare hereditary keratotic skin disease that is autosomal recessive in nature. The typical symptom of lichen planus is a large, dark black or brown colored ichthyosis that covers the entire body. Most infants are born with the appearance of a CollodionBaby, where the outer layer is shed and the skin begins to peel off, occurring over the entire body or confined to the head, abdomen, and legs. In severe cases, the hard flakes may crack in the creases, palms, and feet as the limbs turn, limiting movement and gradually stiffening the joints. Other symptoms include thickening of the palms of the hands and feet, thinning of the hair, eyelid and lip ectropion, finger deformities, and abnormal sweat gland function due to skin damage. The skin condition of patients does not improve easily with age, but the life cycle is comparable to that of the general population. Since the skin of newborns is damaged, there is a risk of excessive water loss, electrolyte imbalance, thermoregulation and infection. Therefore, the humidity and temperature of the patient’s environment must be properly controlled, and attention must be paid to the intake of electrolytes, fluids and calories, as well as the prevention of infections. The incidence of lamellar ichthyosis should be differentiated from the following diseases: 1. common ichthyosis: dry brown rhombic or polygonal scales mainly on the extremities of the limbs and the trunk, often with obvious follicular keratotic papules on the extremities of the upper arms and thighs, with a high incidence of involvement of the palms and toes. The symptoms may be reduced after puberty, but aggravated with age and improper treatment. 2.Sexual interlocking occult ichthyosis: It can be developed after birth or in infants, and the lesions are large and prominent, yellowish-brown or black in color, and the skin is dry and rough, often all over the body, such as the armpit and elbow fossa can also be involved; the back of the abdomen is especially heavy, and if the face is involved, it is limited to the front of the ear and the side of the face, and generally no follicular keratinization occurs, and the skin at the palm and toe is normal, and the lesions do not decrease with age, and sometimes increase instead. 3, epidermolysis bullosa hyperkeratosis ichthyosis: also known as herpetic congenital ichthyosis-like erythroderma: an autosomal dominant genetic disease with high aberration rate clinical rare after birth or a few months after birth can have generalized and site-limited damage generalized when the whole body is born that there is armor-like thick layer of scale armor after birth that is peeled off appearing generalized flushing and scaling peeled off the scales present moist surface erythema can gradually disappear can occur again thicker warty scales Local restriction only in the flexural side of the limbs and wrinkled wall can have thicker fish scale keratinous flakes. 4, laminar ichthyosis: autosomal recessive inheritance after birth, the whole body is an extensive layer of cotton gel-like membrane tightly wrapped, causing eyelid and lip ectropion, and after a few days the membrane is shed, the skin is widely diffuse flushed with gray or gray-brown polygonal or rhombic large scale central fixation edge free, often symmetrical in the whole body to limbs flexural elbow fossa axilla and vulva and other parts more obvious palm and toe hyperkeratosis nail and hair Overgrowth disease process can be delayed throughout life to adulthood erythroderma can be reduced but scales still exist. 5.Squamous erythroderma: Autosomal dominant, a type of ichthyosis, also divided into blister type and non-blister type. The blister type shows flushing all over the body, visible herpes and large epidermal peeling, newly formed keratin layer on the peeling surface, covered with large gray-brown scales in the shape of warts. The non-blistering type shows thickened skin keratinization, the child’s perimeter skin is red, the whole wrapped in a thick keratinous membrane, like fire cotton glue, the wrapped membrane is removed leaving the red skin, appearing thick scales. 6, often ichthyosis: ichthyosis, is a common genetic skin keratosis, the old name ichthyosis, Chinese medicine called snake skin ringworm. It mainly manifests as dry and rough skin on the extensor side of the limbs or trunk, accompanied by rhombic or polygonal scales, with the appearance of fish scale or snakeskin, and can be divided into autosomal dominant common ichthyosis, sex-linked common ichthyosis, congenital ichthyosis-like erythroderma and lamellar ichthyosis, depending on the mode of inheritance.