Cysts are generally not harmful and are often asymptomatic. Often, cysts may not require any treatment at all and just need to be monitored for changes. Occasionally, a cyst may become infected. If it does, contact your dermatologist for treatment guidance. If left untreated, an infected cyst can become painful and dangerous. Although it’s very rare, cysts have developed into skin cancer, so if you notice a cyst is changing or growing, contact your dermatologist.