Scleroderma occurs on the scalp, forehead, lower back and abdomen, and extremities. The lesions are initially light red, slightly edematous rashes of varying sizes, single or multiple. Later, they gradually harden to pale yellow or yellowish white. The surface is smooth and shiny like wax, slightly concave in the center, with hair loss, reduced sweating, dilated surrounding capillaries, and purplish red or deepened pigmentation. In the advanced stage, the skin is atrophic and hypopigmented. The shape of lesions varies, and there are four types of lesions: patchy, banded, punctate and generalized, among which patchy is the most common. The diseases that need to be diagnosed differently from scleroderma are: vitiligo: this disease is a primary limited pigment loss. Atrophic lichen planus: This disease is white punctate damage with a central follicular keratosis or fine dimple. Sclerosing atrophic moss: The primary damage of this disease is white glossy flat papules that fuse into patches with acne-like keratinous plugs on the surface and no pale purplish-red halo at the edges, with pronounced pruritus. Patchy atrophy: This disease presents as a primary atrophic patch that is soft and flaccid. Progressive idiopathic skin atrophy: the disease is preceded by atrophy without a pale purplish-red halo at the edges. Progressive lipid-like necrosis: The disease extends from a red papule to form a scleroderma-like patch with a brown central atrophic area, and features of the pathological tissue can be distinguished from scleroderma. Occupational scleroderma: exposure to vinyl chloride, trichloroethylene, insecticides (such as deodine, heptachlor, sodium dinitro orthocyanate and other workers), the skin can appear scleroderma-like changes. Medically induced scleroderma: drugs such as scramblomycin can cause scleroderma-like skin changes with reversible lesions. Banded scleroderma can also occur after local injection of corticosteroids and disappear on its own in a few months. Intramuscular injection of vitamin K2 can produce scleritis-like subcutaneous tissue inflammation. Chronic graft-versus-host disease after organ transplantation may manifest as limited sclerosing skin lesions. Atrophic slow extremity dermatitis: the disease is limited to the extremities, initially as purple-red nodules with indistinct margins, variable number and size, fusing with each other to form diffuse lesions, and then gradually atrophying. In severe cases, the muscles and bones of the affected limbs are also atrophied, resulting in impaired movement due to arthritis. The skin of the lesion is loosened and wrinkled in the advanced stage of atrophy, which is softer than that of scleroderma. There is no spontaneous remission and treatment with penicillin may be effective. Eosinophilic fasciitis: this disease is a newly discovered connective tissue disease, see the content of the disease for details.