Boils are caused by the commonly occurring Staphylococcus aureus bacteria, and they are not considered to be a sexually transmitted infection, nor are they a symptom of one. According to the Mayo Clinic, boils are infections of the skin that develop a yellow-white head which eventually ruptures and drains. Boils occur anywhere on the body where frequent friction or sweating occur, including the neck, armpits, buttocks and thighs.
While boils are not a sexually transmitted infection, the NYU Langone Medical Center recommends that patients seek medical treatment if any boil appears on the genitalia to determine its cause and make an accurate diagnosis. Because boils are sometimes mistaken for other sexually transmitted infections, it is important to visit a doctor.
According to the Mayo Clininc, boils begin as red, tender lumps that form under the skin when bacteria infect one or more of your hair follicles. The sores typically fill quickly with pus until they burst and begin to heal. When boils are present on the body in places other than the genitalia, the Mayo Clinic recommends a visit to the doctor if the boil lasts longer than two weeks, is extremely painful, or occurs with a fever. Some boils require drainage or antibiotics to heal completely.