**6.1 Stages of Syphilis**

Syphilis infection is divided into four stages with different symptoms that appear in the patient. The symptoms and signs associated with each stage may overlap each other, and symptoms may not appear in order. Some patients have not had any symptoms for years. After the initial infection, the bacterium *T. pallidum* can remain inactive in the body before becoming active many times, and it needs 21 days to show the first symptom after the acquisition of a syphilis infection [5, 29].

**Primary syphilis:** During the primary stage of syphilis, a single sore or multiple sores may be noticed, which usually lasts 3–6 weeks and heals regardless of taking the treatment. The primary stage of anorectal syphilis that comes through anal intercourse appears within 2–10 weeks of exposure. The anal chancre is a small indurated papule that eventually upgraded to anal ulcers; located on the perianal skin or in the anal canal; may be single or multiple; are associated with painless but prominent inguinal lymphadenopathy but heals without treatment in 2–4 weeks. Anal ulcers contrasts with genital ulcers are frequently painful [30, 31]. Even after the sore goes away, continuing the treatment is recommended; this will stop the infection from moving to the secondary stage [29].

**Secondary syphilis:** Four to ten weeks after primary syphilis appears, the spreading of hematogenous untreated syphilis infection leads to secondary stage syphilis [4]. During the secondary stage, the patient may have skin rashes and/or mucous membrane lesions. The rash can appear 2–8 weeks after the chancre develops and sometimes before it heals. The rash may look like rough, red, or reddish-brown spots on the bottoms of the feet and the palms of the hands. This rash does not usually cause itching, but it may be accompanied by wart-like sores in the mouth and sexual areas [29].

The infection is highly contagious during this stage. The symptoms at this stage will go away when the treatment is initiated. Without the right treatment, the infection will move to the latent and tertiary stages of syphilis [1, 5, 29]. The majority of untreated symptoms of syphilis spontaneously resolve after 12 weeks. One-fourth of these untreated patients will experience early latent syphilis [4].

**Latent syphilis:** The latent stage of syphilis is a period when there are no visible signs or symptoms. Without treatment, the infected person continues to have syphilis in his/her body for years. The infection is contagious in the early part of the latent stage and may continue its transmission even without showing symptoms [1, 29].

**Tertiary/Late syphilis:** This is the most destructive stage, in which complications of syphilis appear in patients who have not undergone the required treatment. Tertiary syphilis is very serious and would occur 10–30 years after the infection began. In tertiary syphilis, the disease damages the internal organs, which results in death [1, 4, 29].
