By Allison Evans, assistant managing editor

Christopher Columbus. Oscar Wilde. Al Capone. What do these three historical giants have in common? It is thought that they had syphilis (Al Capone was diagnosed with syphilis during his incarceration in Alcatraz). While these assertions cannot be verified, historical records point to the large number of people who may have contracted the disease. While syphilis feels like a disease of the past, the mounting number of reported cases worldwide suggests that syphilis is as much a modern issue as it once was.

Throughout history, dermatologists have played a key part in the treatment and management of sexually transmitted diseases (STDs) as a majority of these diseases — syphilis included — have skin involvement. This month, Dermatology Word delves into the intersection and subsequent uncoupling of dermatology and syphilology, and how dermatologists can play a key role in the diagnosis and management of syphilis today, as well as national prevention and control efforts. 

An intimate history

Historically, treating syphilis was a standard part of dermatologic care since many initial and later manifestations of the disease are cutaneous or mucocutaneous, said Kenneth A. Katz, MD, MSc, MSCE, a dermatologist at Kaiser Permanente. “Dermatologists were syphilologists and syphilologists were dermatologists.”

In the 1930s, what is now the American Board of Dermatology was incorporated as the American Board of Dermatology and Syphilology. The first meeting of the Academy held in 1938 was the meeting of the American Academy of Dermatology and Syphilology. Two of the meeting’s seven lectures were about syphilis.

Decades later, as syphilis rates decreased to a historic low, “dermatologists weren’t seeing syphilis as much,” said Erin Amerson, MD, a San Francisco dermatologist and medical director of dermatology at Zuckerberg San Francisco General Hospital.

Additionally, JAMA Dermatology was once called A.M.A. Archives of Dermatology and Syphilology before its name was truncated to A.M.A. Archives of Dermatology. “The diagnosis and treatment of patients with syphilis is no longer an important part of dermatologic practice,” wrote the journal’s chief editor in January 1955, due to the decreasing incidence of the disease (AMA Arch Derm. 1955;71(1):1).

Dermatologists became less proficient in syphilis because they didn’t need to be, noted Dr. Katz. For a time, it appeared that syphilis was going the way of the dinosaurs, but this did not happen.

The calm before the storm

In 2000 and 2001, the national rate of reported primary and secondary syphilis cases was 2.1 cases per 100,000 population, a low after a syphilis epidemic occurred in the 1980s. Since 2001, the rate of syphilis has increased across nearly all ages and genders, including rates of congenital syphilis. In 2017, according to the latest available Centers for Disease Control and Prevention (CDC) surveillance data, a total of 30,644 cases of primary and secondary syphilis were reported in the United States (9.5 cases per 100,000 population), a 72.7% increase from 2013.

A disproportionate burden is in certain high-risk groups like men who have sex with men (MSM), especially those living with HIV, and urban dwellers, said Amy Forrestel, MD, assistant professor of clinical dermatology at the University of Pennsylvania. Over the past 15 years, MSM have accounted for 91% of primary and secondary syphilis cases in the United States.

What’s happening?

Unfortunately, there isn’t one reason that explains the increasing prevalence of this disease, but rather, it’s multifactorial, Dr. Forrestel said. Dr. Amerson agreed. In the last five years or so, the rates have dramatically increased, and there’s not much data to tell us exactly what’s happening, she said.

In 1999, the CDC launched a significant public health campaign in an attempt to eliminate syphilis, in which the government invested heavily in resources for outreach, testing programs, outbreak response, and more, Dr. Forrestel said. Some experts have tied the increase in syphilis to reduced federal funding for women’s health and STD clinics. “At some point, if you start investing less in those public health efforts the numbers are going to increase. I think some of that waxing and waning reflects the public health effort that’s put forth,” Dr. Forrestel said. Dr. Amerson agrees that lack of public funding likely contributes to the increase. The jury is out, however, on how much reduced funding has played a role, given that these increases in the rates of syphilis are being reported everywhere in the developed world, and not just in the United States.

Other factors that may be contributing to the syphilis resurgence include epidemiologic trends such as injection drug usage and the advent of pre-exposure prophylaxis (PrEP) for HIV and even the increase in dating and hookup apps. While MSM account for the majority of new cases, the incidence in other demographics is also on the rise.

“We can’t have stereotypes about who we should test for syphilis. There’s enough of it out there that dermatologists need to keep a high index of suspicion no matter who the patient is,” Dr. Amerson said. “Of course, in somebody who’s MSM or anybody with HIV, or has known high-risk sexual behavior, we have to be especially vigilant.”

But, she noted, “Another worrisome trend is that we’re seeing a rise in the rate of syphilis in women as well.” Unfortunately, we’ve reached a threshold in the population where anyone could get the disease, Dr. Amerson noted, which is why there have been spikes in congenital syphilis, which can lead to infection of the fetus in up to 80% of cases and may result in stillbirth or death of the infant in up to 40% of cases.

It’s back!

While dermatologists have a formal education in syphilis, depending on when the dermatologist was in residency, coupled with geographic location, some dermatologists may not have much clinical experience with the disease. “When I trained, I barely saw syphilis and now we see it all the time,” Dr. Amerson said.

View the U.S. map in the sidebar below to see where rates of primary and secondary syphilis are highest in the country.

‘The great imitator’

There are many more patients coming into dermatologists’ offices who most would never suspect of having syphilis, Dr. Amerson said. “Most often, we see a papulosquamous eruption. Whenever you see pityriasis rosea, you should always think about testing for syphilis.”

“The chancre might be mistaken for herpes, for example, while the truncal rash of syphilis might be mistaken for pityriasis rosea, a drug reaction, or a viral exanthem,” Dr. Katz said. Not all chancres are on the genitals, said Dr. Amerson. They can be found in the mouth and anus as well, she said. “There are case reports of chancres on fingers, arms, all over the place.” While the classic chancre is a single painless, firm ulcer, there are plenty of cases of patients with multiple chancres clustered together. The takeaway: The classic presentation isn’t always what you’ll see for primary syphilis.

“I think any time a patient comes in with a relatively asymptomatic rash, syphilis should cross your mind — whether it’s scaly or more nodular. That lack of symptomatology can be a prominent sign,” Dr. Forrestel said. Based on the literature, sometimes dermatologists look for sole and palm involvement as a telltale sign; however, the lack of palm and sole involvement should by no means rule it out.

Another oft-missed indication of syphilis is condyloma lata, Dr. Forrestel noted. A sign of secondary syphilis, condyloma lata can very closely mimic genital warts. Since genital warts are often a sign of an STD, it’s good practice to screen for syphilis as well — for its ability to mimic warts and because the patient might be appropriate to screen anyway, she said.

“Secondary syphilis can be psoriatic, so it can look like psoriasis. It can be annular, so it can look like tinea, or it can be lichenoid. You can get only mucosal involvement and you can get alopecia and nail changes. Syphilis can be confused with almost anything, unfortunately,” Dr. Forrestel said.

Neurosyphilis and ocular syphilis

Over the last five years, there’s been a cluster of ocular syphilis and neurosyphilis that hadn’t been seen in the decade prior, said Dr. Katz, although there isn’t a clear reason why. One of the key takeaways underscored by all the syphilis experts is that both ocular syphilis and neurosyphilis can occur at any stage during the infection, regardless of HIV status.

“Whether you’re seeing a chancre associated with primary syphilis or a rash of secondary syphilis, dermatologists should always do a thorough review of systems,” Dr. Forrestel said. That includes asking about headaches, visual symptoms, ear symptoms, like ringing in the ears, and hearing loss, neck stiffness, weakness, or signs of confusion, she said.

Patients with neurosyphilis need to receive two weeks of intravenous aqueous crystalline penicillin G, Dr. Amerson noted. The single intramuscular injection of benzathine penicillin G is only appropriate for primary, secondary, and early latent syphilis, not for late latent, said Dr. Katz.

It’s important that dermatologists know where they can refer patients with suspected neurosyphilis and ocular syphilis, Dr. Forrestel said. Dr. Katz agrees. “It’s important to ask every patient who has syphilis about manifestations of ocular and neurosyphilis because those manifestations require a referral for specialized treatment and should not be missed because the patient could go blind or deaf if not treated appropriately.”