The rise of syphilis: a call to action for dermatologists
Authors: Hitaishi Mehta, Anuradha Bishnoi, Keshavamurthy Vinay
Journal: The Lancet Infectious Diseases (2024)

We are writing to bring attention to the alarming surge in cases of syphilis and the crucial role dermatologists can play in addressing this public health concern. Syphilis, caused by Treponema pallidum, has increased by 80% in the USA over the past 5 years, as reported by the US Centers for Disease Control and Prevention (CDC).1US Centers for Disease Control and PreventionSexually transmitted infections surveillance, 2022.https://www.cdc.gov/std/statistics/2022/default.htm?s_cid=std2024polDate: 2024Date accessed: February 3, 2024Google Scholar Furthermore, the incidence of congenital syphilis has had a 10-time increase from 2012 to 2022.2US Centers for Disease Control and PreventionVital signs: missed opportunities for preventing congenital syphilis—United States, 2022.https://www.cdc.gov/mmwr/volumes/72/wr/mm7246e1.htm?s_cid=mm7246e1_wDate: 2023Date accessed: February 3, 2024Google Scholar Numerous general factors could have contributed to this upsurge, including increased dating app use, casual sexual encounters, and reduced surveillance of sexually transmitted infections (STIs) during the COVID-19 pandemic. However, these factors also apply to other STIs, such as gonorrhea and chlamydia, which are not surging.1US Centers for Disease Control and PreventionSexually transmitted infections surveillance, 2022.https://www.cdc.gov/std/statistics/2022/default.htm?s_cid=std2024polDate: 2024Date accessed: February 3, 2024Google Scholar This contrast raises the question: what distinguishes syphilis? Pathogen-related factors, including increased transmission risk, diminished antibiotic response, or accelerated replication, might have contributed to this surge and warrant scrutiny, especially amid the penicillin shortage in specific regions.3Seghers F Taylor MM Storey A et al.Erratum to: securing the supply of benzathine penicillin: a global perspective on risks and mitigation strategies to prevent future shortages.Int Health. 2023; (published online Nov 30.)https://doi.org/10.1093/inthealth/ihad087Crossref PubMed Google Scholar However, when one looks closely at the trends, the rise in syphilis incidence is notably attributable to the stark increase in the number of late latent syphilis compared with other stages.1US Centers for Disease Control and PreventionSexually transmitted infections surveillance, 2022.https://www.cdc.gov/std/statistics/2022/default.htm?s_cid=std2024polDate: 2024Date accessed: February 3, 2024Google Scholar The asymptomatic nature of the latent stage means diagnosis is only possible with serological screening tests. The United States Preventive Services Task Force advises routine annual chlamydia and gonorrhoea screening for all sexually active women aged 24 years or younger.4LeFevre ML Screening for chlamydia and gonorrhea: US Preventive Services Task Force recommendation statement.Ann Intern Med. 2014; 161: 902-910Crossref PubMed Scopus (227) Google Scholar However, the syphilis screening is targeted for pregnant individuals and non-pregnant individuals at high-risk of syphilis—including males, men who have sex with men (MSM), people with HIV infection, history of incarceration, sex work, military service, and drug use and also considering factors such as local prevalence, socioeconomic determinants, and sexual network characteristics.5Mangione CM Barry MJ Nicholson WK et al.Screening for syphilis infection in nonpregnant adolescents and adults: US Preventive Services Task Force reaffirmation recommendation statement.JAMA. 2022; 328: 1243-1249Crossref PubMed Scopus (14) Google Scholar The disproportionate rise in latent stage compared with other stages of syphilis suggests that the absence of routine screening for syphilis could underlie the observed surge, and this suggests the need for incorporating routine serological syphilis screening for all sexually active individuals, even if they are not at high risk and are asymptomatic. Since the trends showed a substantial increase in the incidence of syphilis in people aged 30–44 years, the screening for syphilis should be performed in all sexually active individuals, regardless of the age.1US Centers for Disease Control and PreventionSexually transmitted infections surveillance, 2022.https://www.cdc.gov/std/statistics/2022/default.htm?s_cid=std2024polDate: 2024Date accessed: February 3, 2024Google Scholar Given disconcerting trends, especially in congenital syphilis, a comprehensive discussion regarding resource delegation and cost-effectiveness of routine serological syphilis screening is urgently needed, especially regarding the duration of implementation of such screening. Another probable explanation for this rise could be missed diagnosis or misdiagnosis in the initial stages. The complexity and diversity of clinical manifestations of syphilis, often referred to as the great mimic, underscores the importance of dermatologists. Dermatologists are uniquely positioned to identify the disease in incipient stages, given its prominent cutaneous manifestations (figure, appendix), thus steering prompt treatment, preventing complications, and interrupting the chain of transmission.6Forrestel AK Kovarik CL Katz KA Sexually acquired syphilis: historical aspects, microbiology, epidemiology, and clinical manifestations.J Am Acad Dermatol. 2020; 82: 1-14Summary Full Text Full Text PDF PubMed Scopus (60) Google Scholar Although syphilis is well known to dermatologists, familiarity of its manifestations is essential among primary care practitioners and other concerned specialists, especially gynaecologists, paediatricians, and urologists.7Whiting C Schwartzman G Khachemoune A Syphilis in dermatology: recognition and management.Am J Clin Dermatol. 2023; 24: 287-297Crossref PubMed Scopus (6) Google Scholar Opportunistic testing in dermatology clinics, where patients seek services such as genital wart removal, is crucial. Implementing a reverse screening algorithm in routine practice, which commences with treponemal tests for screening and is followed by non-treponemal tests, can enhance the detection of latent infections occasionally missed by the non-treponemal tests.8Hazra A Collison MW Davis AM CDC sexually transmitted infections treatment guidelines, 2021.JAMA. 2022; 327: 870-871Crossref PubMed Scopus (16) Google Scholar This approach also reduces the rates of false positives. Exceptions should be noted for primary syphilis, congenital syphilis, and cases with a history of previously treated infections. The prophylaxis doxycycline, endorsed by the CDC for preventing bacterial STIs in groups at high-risk, has potential for mitigating the rise in syphilis.9US Centers for Disease Control and PreventionGuidelines for the use of doxycycline post-exposure prophylaxis for bacterial STI prevention.https://www.cdc.gov/std/treatment/guidelines-for-doxycycline.htmDate: 2023Date accessed: February 3, 2024Google Scholar Long-term effectiveness needs ongoing research, with crucial vigilance on antibiotic resistance for sustained efficacy. In conclusion, the rise in the incidence of syphilis necessitates a coordinated effort. Dermatologists, with their expertise in recognising mucocutaneous manifestations, play a crucial role. Collaboration, education, and proactive serological testing are important components of a comprehensive response to this public health threat. We declare no competing interests. Download .pdf (.13 MB) Help with pdf files Supplementary appendix