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Syphilis (Lues)

Key Points

  • The treatment of syphilis is based on the duration of infection and the organ systems involved.
  • Five subtypes of syphilis can be distinguished: primary, secondary, or early syphilis of less than 1 year’s duration; infection of indeterminate length, or more than 1 year’s duration; neurosyphilis; congenital syphilis; and syphilis infection in association with HIV infection.
  • When a diagnosis of syphilis is made, evaluation for other STDs and treatment of potentially infected contacts are necessary.

Introduction

Syphilis is caused by infection by the bacterial spirochete, Treponema pallidum, which is sexually and vertically transmitted. Infection rates by syphilis have been rising over the past decade. It presents across a broad clinical spectrum, including many cutaneous signs, that evolves with the duration of the infection and also correlates with the immune status of the patient.

Table 1. Cutaneous and Systemic Findings in Syphilis

Key cutaneous findings Important additional systemic findings
Primary Chancre Lymphadenopathy
Secondary Disseminated papulosquamous eruption including palms/ soles, condyloma lata, mucous patches, moth-eaten alopecia Arthralgias, myalgia, pharyngitis, ocular involvement
Tetriary Erythematous to red-brown nodules, plaques Cardiac and CNS involvement
Neurosyphilis Cranial nerve dysfunction, meningitis, stroke, altered mental status, general paresis, tabes dorsalis
Congenital syphilis Saddle nose Saber shin, Clutton’s joints, Higoumenakis sign, hepatosplenomegaly, neurosyphilis, pneumonitis, Hutchinson teeth, mulberry molars, snuffles (rhinorrhea with bloody mucus)

Neurosyphilis may occur at any time during syphilitic infection. Patients with neurosyphilis should be evaluated for co-infection with HIV. Diagnosis requires a reactive CSF with increased cell count, increased protein content, and a positive CSF VDRL. The serum FTA-ABS or MHA-TP is positive in all cases. Neurologically normal patients with early syphilis do not require CSF examination. CSF examination is required during and after treatments as an index of cure.

Infected infants may be asymptomatic at birth and have negative serologic studies. The initial evaluation requires:

  • A physical examination.
  • Maternal history to include serologic status, treatment, and response to treatment. Adequate treatment of the mother before delivery, except with erythromycin, treats the infant, although if treatment is delayed until late in gestation, stigmata may still appear.
  • CSF examination for cells, protein, and VDRL.
  • Radiographs of the long bones.
  • Examination of any lesions for spirochetes by darkfield or histologic special stains.

HIV infection may alter the natural history of syphilis in two ways: A negative VDRL or RPR can occur with active secondary syphilis; and early CNS relapse after apparently adequate therapy has been observed on multiple occasions. A CSF examination should precede and guide treatment of HIV-infected individuals with latent syphilis or syphilis present for 1 year or more, or of unknown duration. If CSF examination is not possible, treat for presumed neurosyphilis. HIV-positive persons with CNS findings should be evaluated for possible neurosyphilis.

For all patients with neurosyphilis, and infants with possible neurosyphilis, in addition, a CSF examination must be repeated 6 months following treatment. Adequate therapy is determined by a normal CSF cell count and a falling protein content. The VDRL may not return to negative. CSF examination in documented neurosyphilis (with abnormal CSF findings) is continued at 6-month intervals for 2 years. A normal CSF at 1 year is evidence of cure.

Diagnosis can be made on the basis of clinical findings, darkfield examination, nontreponemal tests (RPR or VDRL), treponemal serologies (FTA-Abs or MHA-TP).
When neurosyphilis is suspected, CSF should be examined for increased cell count, increased protein content, a positive CSF VDRL, and serum FTA-ABS or MHA-TP (both are usually positive in all cases).

The treatment of syphilis is based on the duration of infection and the organ systems involved. Five groups can be distinguished: primary, secondary, or early syphilis of less than 1 year’s duration; infection of indeterminate length, or more than 1 year’s duration; neurosyphilis; congenital syphilis; and syphilis infection in association with HIV infection. In all cases of syphilis it is important to examine for and treat other STDs, and to trace and treat all contacts. Syphilis cases should be reported to the local health department. Infected individuals may resume sexual activity after skin lesions, if present, are healed, or after therapy is complete.