Summarize this article:

(Have your partner check themselves as well.) The sores often appear as open, wet ulcers, or painless sores. These sores, caused by infection with syphilis bacteria, typically appear between 10 days and three months after exposure. They appear on the region of the body infected (such as the penis, vagina, tongue, lips, anus) and heal up, though the disease remains in the body. Secondary syphilis can reappear later on. These symptoms begin three to six weeks after the disappearance of the primary syphilis sore and include:   Rash with ¾ inch red or brownish sores — This is the most classical sign of secondary syphilis.  The rash is characterized as a rash (a flat, red area covered with bumps) over the trunk and extremities that includes the palms and soles of the hands and feet Fever Headache Sore throat Anorexia Muscle pain Weight loss Alopecia Gastrointestinal Findings Musculoskeletal Problems Neurological and Ocular Findings Swollen lymph nodes General feeling of malaise This is dangerous and can cause neurological symptoms including uncoordinated movement and changes in behavior. In addition, secondary syphilis can lead to tertiary syphilis, which may spread to organs including and cause life-threatening complications. Neurosyphilis is difficult to diagnose and usually spinal fluid must be tested to confirm. This is a dangerous disease that can cause permanent damage and even death if left untreated. Talk to your doctor immediately and get tested.

Summary:
Check your genitals, mouth, and anus for primary syphilis sores. Evaluate yourself for signs of secondary syphilis. Be aware that syphilis may, at any point in the course of the infection, spread to the nervous system. Seek medical care if you have any of the symptoms listed above or suspect you may have syphilis.