Last week, the Los Angeles County health department issued a warning against ocular syphilis — a form of sexually transmitted disease that can blind those who become infected — following the cluster of cases seen in Seattle/King County and San Francisco since December. In Washington State, six cases of ocular syphilis were diagnosed, including two cases that resulted in blindness and several causing a significant decline in vision. While the LA health department has not yet identified a cluster, it is investigating two independent cases that have occurred within the California county.

The warning issued by the LA health department requests health care providers be vigilant for potential cases particularly among “men who have sex with men and HIV‐infected persons.”

The number of reported syphilis cases increased by nearly 11 percent between 2012 and 2013. In the United States, 56,471 cases of syphilis, which is caused by the bacterium Treponema pallidum, were reported in 2013. While the incidence was highest in women 20 to 24 years of age and in men 20 to 29 years of age, three out of four reported cases were among men who have sex with men (MSM).

Cases of ocular involvement are rare and typically occur 10 weeks to six months after infection.

However, high rates of HIV co-infection have been seen in the recent outbreaks, ranging from 20 percent to 70 percent. The genital sores caused by syphilis make it easier to transmit and acquire HIV infection during sex. In fact, the risk of HIV infection is two to five times greater when syphilitic sores are present.

Signs and Symptoms

Syphilis is easy to diagnose — simply ask any health care provider for a blood test — and very easy to cure in its early stages. Many people are unaware they have become infected with syphilis, since they may not show any obvious symptoms for years. In the primary stage, syphilis may cause a sore, called a chancre, appearing on the exact spot where syphilis entered the body. Generally, chancres are painless, small, and round. They heal without treatment and last three to six weeks.

Without treatment, syphilis progresses to the second stage, which involves a rash and lesions.

An itchless rash appears on one or more areas of the body. Generally, it appears as rough, red, or reddish brown spots, usually on the palms of the hands and the soles of the feet. These rashes may appear as the chancre is healing or several weeks after the chancre has healed. Sometimes the rash is faint or it may resemble the flush caused by other diseases. Secondary syphilis may also include fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and fatigue. These signs will resolve with or without treatment.

Syphilis moves onto the latent (hidden) stage in about 15 percent of all people who have not been treated. Symptoms may appear 10 to 20 years after the infection was acquired and may include damage to the internal organs, including the brain, nerves, eyes, heart, blood vessels, liver, bones, and joints. Signs include difficulty coordinating muscle movements, paralysis, numbness, gradual blindness, and dementia.