Diagnosis

Syphilis

Etiology

Cause [ckb]

• Treponema pallidum is a spiral-shaped bacteria (spirochete)

• Incubation period: 3 to 4 weeks

• Slow metabolic rate, taking an average of 30 hours to multiply

Pathophysiology [qzt][ckb]

1. Transmitted by:

   • Intimate contact with infectious lesions (most common)

   • Blood transfusion

   • Transplacentally from an infected mother to fetus in utero (congenital)

2. Treponema pallidum rapidly penetrates intact mucous membranes within a few hours and enters the lymphatics and blood to produce systemic infection.

3. If untreated, it progresses through 4 stages: primary, secondary, latent, and tertiary.

   1. Primary syphilis:

      • Development of a highly infectious painless chancre at the site of transmission

      • Localization: Genitals, digits, nipples, tonsils, and oral mucosa

      • Chancre consists of mononuclear leukocytes, macrophages, and lymphocytes

      • Healing occurs within 3-12 weeks with considerable residual fibrosis

      • Resolve without treatment and 25% may go to secondary phase if untreated

   2. Secondary syphilis: 4-10 weeks after the appearance of the primary lesion

      • The spirochetes multiply and spread throughout the body

      • Systemic manifestations: Headache, malaise, fever, myalgia, arthralgia, lymphadenopathy, pharyngitis, hepatosplenomegaly, alopecia, and maculopapular rash involving the palms and soles

      • Resolve without treatment and the patient may enter latent phase if untreated

   3. Latent syphilis: secondary syphilis have resolved, but patients remain seroreactive

      • 1/3 of untreated latent syphilis patients go on to develop tertiary syphilis

   4. Tertiary syphilis (rare): slow inflammatory damage over months to years

      • Gummatous syphilis:

        • Necrotizing granulomas (gummas) in the liver, bones, testes or any organ

      • Cardiovascular syphilis (80-85%)

        • Aortitis

        • Aneurysm in the ascending aorta due to chronic inflammatory destruction

        • Aortic valve insufficiency may result

      • Neurosyphilis (5-10%)

        • CSF: high protein, low glucose, high lymphocytes, positive syphilis serology

        • Damage to the blood vessels of the meninges, brain, and spinal cord

        • Parenchymal neurosyphilis: Meningitis, hemiplegia, stroke, aphasia, seizures, spinal neuroarthropathy, tabes dorsalis (demyelination of dorsal medulla spinalis)

        • Paresis, areflexia and impaired vibration/proprioceptive/pain/temperature sensation leading to a wide-based gait

   5. Congenital syphilis (infection of the fetus in utero):

      • A high rate of spontaneous abortion and stillbirth

      • Widespread condylomata lata and rash, and mucopurulent rhinitis

      • Bone/teeth deformities (saddle nose, saber shins, Cluttons joints, Hutchinsons teeth, mulberry molars), general paresis, deafness and blindness

Complications [ckb]

• Neurological complications: meningitis, stroke, cranial nerve palsies, tabes dorsalis, dementia, and general paresis

• Cardiovascular complications: aortitis, aortic regurgitation, carotid ostial stenosis

• Granulomatosis lesions (gummas) in various body organs

• Neonatal infections --> congenital syphilis --> adverse pregnancy outcomes

Epidemiology

Incidence per 100.000 [vsr][69w][qzt][9fa]

Approach

• Blood test

• Serelogy

• Polymerase chain reaction

• Microscopy (darkfield)

• Biopsy

• Lumbar tap

• CT abdomen

• CT thorax

• CT caput

• MR caput

• Ultrasonography of the fetus when the disease has been diagnosed during the second half of the mother's pregnancy

Treatment

Penicillin is the preferred bacteriocidal antibiotic for all stages of syphilis [ckb]

1. Primary, secondary, and early latent syphilis: Single dose Penicillin G 2.4 million units

2. Tertiary/late latent syphilis: Penicillin G 2.4 million units intramuscular (for 3 weeks)

3. Neurosyphilis: Penicillin G 3 to 4 million units IV every 4 hours daily for 10 to 14 days

4. Alternatives:

   • Doxycycline 100 mg orally (PO) twice daily for 14 days

   • Ceftriaxone 1 to 2 gm IM or intravenously (IV) daily for 10 to 14 days

   • Tetracycline 100 mg PO 4 times daily for 14 days

5. Congenital Syphilis:

   Penicillin G 50,000 units/kg body weight/dose IV every 12 hours during the first 7 days after birth, then every 8 hours for 10 days

Differential diagnoses

Behcet's disease, Brain tumor, Candidiasis, Chancroid, Chlamydia, Contact dermatitis, Dementia, Eczema, Encephalitis, Erythema multiforme, Fungal infection, Granuloma inguinale, Heart failure, Herpes simplex, Herpes zoster, HIV, Human papillomavirus, Lymphogranuloma venereum, Lymphoma, Meningitis, Mononucleosis, Pityriasis rosea, Psychosis, Rocky mountain spotted fever, Sarcoidosis, Stroke, Urinary tract infection, Uveitis, Yaws