Syphilis
The initial symptom of syphilis is a painless open sore that usually appears on the penis, in the vagina, or on the skin around either sexual organ. Untreated syphilis may go on to more advanced stages, including a transient rash and, eventually, serious involvement of the heart and central nervous system. Syphilis infections can be treated with antibiotic therapy.
Learn more about syphilis.
