Ichthyosis vulgaris is an autosomal dominant form of ichthyosis, and is divided into blistering and non-blistering forms. The blister type shows flushing all over the body, with herpes and large epidermal peeling, and the 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, with the child’s entire body red and wrapped in a thick keratinous membrane, like fire cotton glue, which is removed to leave a red skin and thick scales. So how is ichthyosis vulgaris-like erythroderma diagnosed? Here is a brief introduction. The diagnosis of ichthyosis-like erythroderma 1, the age of prevalence: common in adolescents, the symptoms are not obvious at birth, about 95% before the age of three. 2.Preferred site: extensor side of the limbs and back, of which the front side of the calf is the most obvious. 3, the characteristics of the lesions: the lighter the dry skin in winter, the surface has fine scales; slightly heavy for light brown to dark brown diamond-shaped or polygonal scales, appearance like fish scales, but generally no conscious symptoms. We all know that ringworm-like red skin is a kind of skin disease, and the disease is also more difficult to cure, it will bring great harm to the skin, so we can not ignore, to understand more about its diagnosis, and then do a good job of prevention, to do early detection, early diagnosis, early treatment, so that the disease can be killed in the cradle, so that the skin will not be seriously affected.