In the end, his combination of rash, malaise, liver and kidney problems, facial paralysis, and swelling all fit with syphilis. However, syphilis that affects the liver is rare, occurring in less than 10 percent of cases, which made the diagnosis particularly difficult.

Doctors think the infection was likely in the second stage. In the first stage, people just develop a chancre at the site of the infection. The chancre develops usually around a month after an exposure, is painless, and resolves on its own. Then the second stage emerges with the bacterial infection going systemic, usually with rash, malaise, loss of appetite, joint pain, swelling, fevers, and sore throat—similar to the man’s symptoms. After that, the infection can become latent (third stage) before reemerging in the tertiary (late stage), which can manifest in various ways, including with the destruction of the heart, central nervous system, and organs.

While late-stage syphilis can show up years or even decades after an initial infection, the secondary stage doesn’t, the doctors note. “Secondary syphilis typically emerges within the first year after untreated primary infection and only rarely beyond 4 years,” they wrote in the report. It’s possible an immunosuppressing drug, like the steroid he took for his facial paralysis, could reactivate a latent infection, but once reactivated, it would be a late-stage infection, not a secondary one.

Although the man’s STI history decades ago led the doctors to the right diagnosis, it doesn’t explain the current infection. A “more recent, unreported exposure must be considered,” the doctors wrote, but, ultimately, the timing and source of the infection remain unknown.

With a treatment of antibiotics, the man made a full recovery. His doctors note that local health authorities would be contacted to track down and notify the man’s actual sexual partners. How things went with the man’s wife also remains unknown.