Seeing Intraocular Inflammation? Consider Syphilitic Uveitis

NEW ORLEANS — The rate of syphilitic uveitis cases jumped in the U.S. from 2011 to 2016, and there’s no sign cases have gone down in the years since, a researcher reported.

An estimated 3,585 related hospitalizations occurred (0.13 per 100,000 population) from 2010-2016, according to David Hinkle, MD, of Tulane University School of Medicine in New Orleans. In addition, after dipping from 2010-2011, cases rose from 2011 (0.08 per 100,000 population) to 2016 (0.16 per 100,000 population), he said in a presentation at the American Academy of Ophthalmology annual meeting.

“After a long period in which the number of cases of ocular syphilis was low and relatively constant, the rate is now increasing,” Hinkle told MedPage Today.

Using data from the Nationwide Inpatient Sample (NIS), Hinkle’s group found more than 400 cases were reported in 2010, with a dip to just above 200 in 2011. From 2011-2016, case numbers mostly rose steadily, reaching about 550 in 2016.

Hinkle said he’s seen evidence of this rise in his own practice. “For the past 20 years, I have seen zero to two cases, on average, each year,” he said. “At the recent [2021] American Society of Retina Specialists meeting, we reported 10 cases during 2019, a ten-fold rise over historic averages during the previous 10 years,” although he cautioned that data from the NIS is 3 years behind.

In a separate 2021 International Ophthalmology report, Hinkle and colleagues described 16 cases of syphilitic uveitis. “Some patients were referred to me because they were treated with steroids without improvement, which frequently suggests an underlying infection,” he said. “Others had severe vision loss out of proportion to the amount of inflammation present in the eye. There are several forms of posterior syphilitic uveitis — multi focal choroiditis, punctuate inner retinal syphilis, syphilitic placoid chorioretinitis, and acute retinal necrosis, which mimic other conditions.”

Syphilitic uveitis occurs when the bacteria that causes syphilis crosses from the bloodstream into the eye, explained Justine Smith, MBBS, of Flinders University in Adelaide, Australia, to MedPage Today. “This can occur during all stages of syphilis, so it can occur early or late in the course of the disease.” Smith was not involved in the study.

U.S. syphilis rates have risen since reaching an all-time low about 20 years ago, according to the CDC. Nearly 130,000 cases were reported in 2019, an increase of 11.2% over 2018, with more than 83% in men. An estimated 56.7% of male cases in 2019 were in men who have sex with men (MSM). However, cases are rising in women (up 178.6% from 2015-2019), the CDC reported, while there are signs of stabilization among MSM.

Hinkle said that “when a patient is diagnosed with ocular syphilis, we admit them to the hospital for a full medical evaluation and treatment, which typically includes a lumbar puncture, IV penicillin, and checking for other infections. Many patients have a rash on their palms. Blood tests are fairly accurate. Penicillin treatment is curative.”

Hospitalization “is somewhat controversial depending on whether you consider ocular syphilis to represent neurosyphilis,” he added. “We cannot prove in every case that the central nervous system is infected, but it frequently is. There are other treatment regimens which are less intensive than 2 weeks of IV penicillin, but most have a higher failure rate.”

Of all cases analyzed in the current study, the median age was 45, although the age range was wide with 1.79% ages 1-19, 5.47% ages 70-79, and 3.04% ages ≥80. The majority of cases were in white (38.19%) men (78%). A little less than a quarter of the cohort had comorbid HIV infection. The median length of stay in the hospital for syphilitic uveitis was 6 days. Also, 38.6% were in the lowest median income quartile, and just 12.4% were in the highest.

Hinkle advised that syphilis should be considered in every case of uveitis, while Smith suggested that patients with suspected uveitis should be tested for syphilis, as “delay in making the diagnosis and starting antibiotic therapy can result in vision loss in syphilitic uveitis.”

Hinkle pointed out that “many patients recover most or all of their vision if treatment is given before irreversible damage occurs.”