Tuesday, September 6, 2022

Neurosyphilis, ocular syphilis, and otosyphilis are don't-miss diagnoses

 - Kenny Lin, MD, MPH

When a patient with a history of migraine headaches presents with a "severe frontal headache and left-eye blurred vision and pain," neurosyphilis is unlikely to be foremost in the differential. Even after she mentions a two-month history of a diffuse maculopapular rash, clinicians may feel reassured because it doesn't involve the palms and soles. But syphilis, the great imitator, was in fact the eventual diagnosis in this patient, the subject of a case report published in Cureus.

In the August issue of AFP, Dr. Jennifer Jones-Vanderleest reviewed detection and treatment of neurosyphilis, ocular syphilis, and otosyphilis, which can occur at any stage of syphilis regardless of immune status. Early neurosyphilis (within the first few years of infection) can present with "headache, dizziness, altered mental status, cranial neuropathies, motor and sensory deficits, meningitis, or stroke." Neurosyphilis is diagnosed with the combination of neurologic signs and symptoms and reactive syphilis serology and cerebrospinal fluid (CSF) tests. The 2021 Centers for Disease Control and Prevention (CDC) Sexually Transmitted Infections Treatment Guidelines recommend that patients with neurosyphilis be treated with 18 to 24 million units of aqueous crystalline penicillin G per day for 10 to 14 days, administered as a continuous infusion or 3 to 4 million units intravenously every 4 hours. These patients should be tested for HIV and be offered HIV preexposure prophylaxis if HIV negative. After treatment, normalization of the serum RPR titer predicts normalization of CSF parameters; thus, repeated CSF sampling is not needed unless the patient is HIV positive and not receiving antiretroviral therapy.

As I discussed in a previous AFP Community Blog post, the incidence of syphilis in the U.S. has been rising for the past two decades due to stagnant health department funding for contact tracers and the recent impact of the COVID-19 pandemic. Far from being ancient history, "in 2020, 133,945 cases of all stages of syphilis were reported, including 41,655 cases of primary and secondary syphilis," according to the CDC. Although a disproportionate number of cases occur in men who have sex with men, rates in women have increased sharply since 2016.

A draft recommendation statement from the U.S. Preventive Services Task Force (USPSTF) reaffirmed screening nonpregnant adolescents and adults at increased risk for syphilis infection. The USPSTF recommends that all pregnant patients be screened for syphilis as early as possible in pregnancy. The American Academy of Pediatrics and the American College of Obstetricians and Gynecologists recommend rescreening women at high risk for syphilis at 28 weeks of gestation and again at delivery to prevent congenital syphilis.