Many anal and systemic lesions can directly or indirectly lead to ulcers around the anus. First, perianal eczema can cause the phenomenon of skin breakdown around the anus. Perianal eczema is caused by a variety of internal and external factors, including endocrine imbalance and anal lesions, resulting in a long-term moist environment around the anus can cause the appearance of this symptom. Secondly, long-term poor diet and external environmental stimulation, resulting in allergic reactions will also cause this symptom to appear. Long-term allergies can cause the skin around the anus to become red, swollen, and itchy, and the ulcers can be formed by scratching with hands. Finally, we need to be alert to the phenomenon of perianal ulcers caused by sexually transmitted diseases such as syphilis, which generally cause more serious itching and erosion. So for the symptoms of perianal ulcers, you should promptly go to the hospital for examination and treatment.