Dermatology’s history, role in treating STIs
Now, mpox joins the list.
Dermatologists are on the front lines in the ongoing battle to prevent and treat sexually transmitted infections.
“Dermatology as a specialty began from a study of syphilology because syphilis causes so many, many skin rashes,” said Kieron Leslie, MBBS, professor of dermatology at the University of California, San Francisco (UCSF) School of Medicine. “Similarly, condyloma, mpox, and many other sexually transmitted infections (STIs) are primarily diseases of the skin. When someone comes in with a lesion on the face, the hands, the trunk, they may not share that they also have genital lesions. You need to have an index of suspicion that this might be an STI.”
Thinking outside the pox
Dr. Leslie opened “F014 – HIV and STIs: Hot Topics” with an update on the latest skin disease to jump from animals to humans, mpox. Since the 1950s, mpox had been considered a zoonotic infection endemic to parts of Africa that can jump from animals to humans, but human-human transmission was rare. That changed in 2022 when mpox suddenly surged to pandemic status. Spread largely, but not exclusively, through sexual contact, mpox can present as a mild rash to more painful and severe rashes and anogenital lesions.
The good news, according to Dr. Leslie, is that incidence rates in the United States have fallen significantly since the summer of 2022. The drop is likely due to a combination of aggressive vaccination, emphasis on safe sex practices, and widespread infection among the most susceptible populations.
“Dermatologists need to be aware of the morphology of mpox and other STIs because cases continue to present,” Dr. Leslie said. “Symptom control is standard of care for mild disease with analgesia for more severe forms. For severe disease, antivirals potentially active against poxvirus are appropriate.”
Jump on STOMP
The primary antiviral is tecovirimat, approved under an Emergency Use Authorization (EUA). The agent is also being evaluated in STOMP, the Study of Tecovirimat for Human Mpox.
“For patients who present with mpox, we recommend they get enrolled in STOMP,” he said. “Tecovirimat has been evaluated in phase I safety trials and is effective in monkeys, but efficacy in humans has not been evaluated. We hope STOMP will answer the question. Mpox remains a long-standing infectious disease that presents in the skin. Dermatologists need to be aware of what the rashes and lesions look like and be able to refer to appropriate treatment.”
Making safe sex even safer
Practitioners need to be equally familiar with syphilis, HIV, condyloma, and other STIs and the latest prevention strategies. And although treatments are available, prevention is preferred.
Safe sex practices can make a significant difference, Dr. Leslie said. So can vaccination, which has dramatically reduced the incidence and prevalence of condyloma and other sequelae of human papilloma virus (HPV) infection.
The Advisory Committee on Immunization Practices (ACIP) recommends HPV vaccination for all individuals up to the age of 26 and up to age 45 based on individual factors. HPV vaccination is not recommended for older individuals based on both the likelihood of prior HPV infection and the generally lower immune response in older individuals.
PrEP, preexposure prophylaxis, has been used to prevent HIV transmission for a decade, as has PEP (post exposure prophylaxis), according to Albert Liu, MD, MPH, assistant clinical professor at the UCSF School of Medicine and director of HIV Prevention, San Francisco Department of Public Health. The same PrEP-PEP approach has been extended to syphilis using doxycycline, a perennial treatment of choice for acute and secondary syphilis.
“Using doxy as PrEP and PEP is new for syphilis, but the strategies are well established and successful in HIV,” Dr. Liu said. “Dermatologists need to understand that there are highly effective prevention strategies for HIV and syphilis and be comfortable talking with patients about their sexual history and activity.”
