Ulcers with a worm-like appearance are caused by skin ulcers, which are usually limited skin tissue defects caused by trauma, microbial infection, tumors, circulatory and neurological dysfunction, immune dysfunction, or congenital skin defects. Traumatic ulcers are often caused by physical and chemical factors acting directly on the tissues. Microbial infectious diseases are mostly caused by bacteria, fungi, spirochetes, viruses, etc. that cause tissue destruction, nodule or tumor breakdown, and vasculitis ulcers caused by immune abnormalities. It is formed by necrosis of tissues due to arterial or small arteritis, and circulatory or neurological dysfunction is a nutritional disorder causing tissue necrosis such as varicose veins, leprosy, ulcers, etc. 1.Bacterial diseases: boils, carbuncles, cellulitis, sweat gland infection, skin tuberculosis, earning sores, skin anthrax, nasal anthrax, skin diphtheria, necrotizing acne, lower barren type pyoderma, leprosy, tropical ulcer mycobacterial ulcer, pool granuloma, oral tuberculosis ulcer. 2.Fungal diseases Cryptococcosis of the skin, histoplasmosis, coccidioidomycosis, Aspergillosis, pediculosis, actinomycosis, nocardia, ringworm, pustulosis, cutaneous trichomycosis. 3.Viral diseases Hand, foot and mouth disease foot and mouth disease. 4.Parasitic diseases Skin amoebiasis Skin fly maggot disease. 5.Sexually transmitted diseases genital sores, syphilis, soft subcutaneous sores inguinal granuloma, venereal lymphogranulomatosis. 6, allergic skin disease fixed drug rash. 7.Vasculitis and vascular diseases Nodular polyarteritis, allergic vasculitis. Thrombo-occlusive vasculitis, papulonecrotic tuberculosis rash, sclerosing erythema, gangrenous. Pyoderma, lethal midline granuloma, occlusive arteriosclerosis, stasis dermatitis, Raynaud’s disease. 8.Physical diseases Radioactive dermatitis, frostbite, decubitus ulcer. 9.Occupational skin diseases Chromium-nickel, sodium, zinc, cobalt, hydrochloric acid sulfuric acid, hydrofluoric acid, sodium hydroxide, sodium carbonate can cause skin ulcers. 10.Autoimmune disease Leukoaraiosis. 11.Neoplasms Eczema-like carcinoma, eczema-like carcinoma, basal cell carcinoma, squamous carcinoma, malignant melanoma, sebaceous gland carcinoma, chapter-like granuloma, malignant histiocytic hyperplasia, hair sheath carcinoma fibrosarcoma, proliferative erythema, verrucous carcinoma, multiple plasma cell tumors. 12.Other continuous limb dermatitis, nodular fat necrosis, fatty granuloma, foot penetrating ulcer, aphthous stomatitis noma glans, acute female genital ulcer.