👉 Syphilis, also known as syphilis, is a sexually transmitted infection (STI) that affects the immune system. It's caused by a bacterium called Treponema pallidum. Symptoms can include fever, chills, fatigue, muscle pain, and swollen lymph nodes in the neck or jaw. People with syphilis are at higher risk of developing complications such as blindness, heart disease, and cancer. The term "syphiliphobia" is a medical condition that