What are the stages of syphilis and how is each stage treated?

Staging and Treatment of Syphilis

Syphilis is classified into four distinct stages - primary, secondary, latent, and tertiary - each requiring specific treatment regimens based on disease progression.

Stages of Syphilis

Primary Syphilis

• Clinical presentation: Characterized by a painless ulcer (chancre) at the site of infection, typically in the genital, anal, or oral region 1
• Infectivity: Highly infectious stage
• Diagnosis: Definitive diagnosis through darkfield microscopy or direct fluorescent antibody tests of lesion exudate 1
• Treatment: Benzathine penicillin G 2.4 million units IM in a single dose 2

Secondary Syphilis

• Clinical presentation: Occurs 4-10 weeks after primary infection with:
  • Widespread skin rash (can be macular, papular, papulosquamous, or nodular)
  • Mucocutaneous lesions
  • Generalized lymphadenopathy 1
• Infectivity: Highly infectious stage
• Treatment: Benzathine penicillin G 2.4 million units IM in a single dose 2

Latent Syphilis

• Definition: Seroreactivity without clinical manifestations 1
• Subcategories:
  1. Early latent syphilis: Acquired within the preceding year, diagnosed by:
     • Documented seroconversion or fourfold increase in nontreponemal test titer
     • Previous symptoms of primary/secondary syphilis
     • Sexual contact with a partner with documented early syphilis 1
  2. Late latent syphilis or latent syphilis of unknown duration: All other cases of latent syphilis 1
• Infectivity: Not sexually transmitted but can affect fetus during pregnancy
• Treatment:
  • Early latent: Benzathine penicillin G 2.4 million units IM in a single dose
  • Late latent or unknown duration: Benzathine penicillin G 2.4 million units IM weekly for 3 consecutive weeks (total 7.2 million units) 2

Tertiary Syphilis

• Clinical presentation: Occurs years to decades after initial infection with:
  • Gummatous lesions (granulomatous lesions in various tissues)
  • Cardiovascular syphilis (aortitis, aortic aneurysm)
  • Late neurological complications 1
• Infectivity: Not infectious (except neurosyphilis CSF)
• Treatment: Benzathine penicillin G 2.4 million units IM weekly for 3 consecutive weeks (total 7.2 million units) 2

Neurosyphilis (can occur at any stage)

• Clinical presentation: May be asymptomatic or present with meningitis, stroke, cranial nerve dysfunction, or paresis
• Diagnosis: CSF examination showing pleocytosis, elevated protein, or positive VDRL
• Treatment: Penicillin G aqueous 18-24 million units IV daily, administered as 3-4 million units every 4 hours for 10-14 days 2

Alternative Treatments for Penicillin-Allergic Patients

For non-pregnant patients with documented penicillin allergy:

• Primary, secondary, or early latent syphilis: Doxycycline 100 mg orally twice daily for 14 days 2, 3
• Late latent syphilis: Doxycycline 100 mg orally twice daily for 28 days 2, 3

For pregnant patients or patients with neurosyphilis who are allergic to penicillin:

• Penicillin desensitization followed by appropriate penicillin treatment is required 2

Follow-Up Recommendations

• Quantitative nontreponemal tests (VDRL or RPR) at 3,6,12, and 24 months after treatment 2
• Successful treatment is indicated by:
  • Resolution of clinical symptoms
  • Fourfold decrease in nontreponemal test titers within 6 months (primary/secondary) or 12-24 months (latent) 2
• Consider treatment failure or reinfection if:
  • Clinical signs/symptoms persist or recur
  • Sustained fourfold increase in titer
  • Failure of initially high titers to decrease fourfold within appropriate timeframe 2

Important Clinical Considerations

• All patients with syphilis should be tested for HIV infection 2
• CSF examination is indicated for patients with neurologic/ophthalmic symptoms, evidence of active tertiary syphilis, or treatment failure 1
• Sexual contacts within 90 days prior to diagnosis should be treated presumptively, even if seronegative 2
• Pregnant women with syphilis must complete the full course of treatment appropriate for their disease stage 2

Remember that proper staging of syphilis is crucial for determining the appropriate treatment duration and follow-up protocols to prevent complications and ensure cure.