A skin infection occurs when harmful bacteria, viruses, or fungi invade the skin, leading to inflammation and other symptoms. Common types include bacterial infections like impetigo, viral infections such as herpes, and fungal infections like athlete's foot. Symptoms often include redness, swelling, pain, and sometimes pus or blisters. These infections can develop from cuts, scrapes, or other skin injuries, and they may spread through direct contact with an infected person or contaminated surfaces. Treatment typically involves antibiotics for bacterial infections, antiviral medications for viral infections, and antifungal treatments for fungal infections.