Scaling is one of the most common secondary skin lesions in dermatological diseases. It is produced by the epidermis of the skin and is mostly seen in the red patches and macules of superficial inflammatory skin diseases. While in larger, deeper in, located in the deep dermis, subcutaneous tissue and fat layer of the nodules, cysts J membrane inflammation and tumors, because of its deeper site, far from the epidermis and superficial dermis, so scaling is less common. In the normal epidermis keratinocytes are keratin-forming cells, generally consisting of four layers: namely, the lowermost layer is the basal cell layer, the uppermost layer is the spiny layer, the granular layer, and the outermost one is the stratum corneum. Should be distinguished from the following symptoms 1, white furfur, also known as simple furfur, sun exposure can cause the onset, mostly in children, spring prone. Rash for pigment slightly hypopigmented patches, dry coarse with fine small bran batch-like fine flakes. Mostly see in face, upper arm, neck, shoulder. 2, even circle condition furfuraceous rash for a mild keratosis skin disease, the cause is unknown. The lesions are round or oval brown patches, size about 5-20cm diameter. The boundary is clear, not elevated, the surface has fine wrinkles, overlaid with filmy bran-like fine flakes, clinging to the skin is not easy to peel. It occurs in the abdomen and waist area. 3.Unusual ichthyosis is incomplete exogamous. Autosomal dominant inheritance. Brownish-black ichthyosiform keratinized scaly flakes appear on the back, extensor side of limbs and face a few months after birth, which are not easily peeled off by clinging to the skin. Dry skin, no sweating, heavy in winter and light in summer. Often combined with hand and foot palm keratosis. 4.Asbestosis furfuraceous rash The cause is unknown. Characterized by removable white tube sheath from the root of the hair, surrounded by hair dryness. The distal end of the hair has asbestos-like carrier soft and thick white scales, forming shingles; but the hair and scalp without any damage, and no inflammation. 5, squamous follicular keratosis The cause of the disease is unknown, and it occurs in young and middle-aged people. The lesions are thin scaly flaky keratinization, the center of which has a black dot keratinization consistent with the mouth of the hair follicle, the flakes are round, the edges are free, surrounded by a slightly hypopigmented halo. The central black spot remains after the scales fall off. The lesions are mostly on the lateral femur, buttocks and lumbar region. No conscious symptoms, heavy in winter and light in summer.