Over the past two decades, a clear pattern has emerged: while HIV infection rates are declining thanks to prevention techniques such as PrEP and ‘treatment as prevention’, rates of bacterial STIs are increasing. In particular, syphilis, gonorrhoea and chlamydia are on the rise. Post-exposure antibiotics, such as doxycycline (DoxyPEP), have been shown in studies to be effective against syphilis and chlamydia, but not against gonorrhoea, due to increasing antibiotic resistance.
The increasing use of antibiotics such as doxycycline for prophylaxis carries significant risks, particularly the development of resistant bacterial strains. De Vries emphasises the importance of rational antibiotic use, as uncontrolled use could hasten the point at which antibiotics like ceftriaxone fail to treat gonorrhoea. It is predicted that by 2050, 10 million people worldwide could be dying each year from untreatable bacterial infections if antibiotic resistance continues to increase.
Dermatologists play a crucial role in the detection and treatment of STIs such as syphilis and mpox. Their expertise in interpreting clinical skin lesions makes them indispensable players in STI diagnostics. At the same time, de Vries points out that dermatology clinics are often unable to respond quickly enough to acute infections, which is why training for other medical professionals is essential.
While DoxyPEP has shown good efficacy in preventing syphilis and chlamydia in four studies, there are concerns about its effects on the microbiome and the development of resistance. De Vries emphasises that there is currently insufficient data to recommend the widespread use of DoxyPEP. He also suggests that asymptomatic chlamydia infections should not be routinely tested, as these rarely lead to serious long-term consequences.
The prevention of bacterial STIs faces new challenges, particularly due to the increasing resistance to antibiotics. While postexposure antibiotics such as doxycycline are promising against certain infections, responsible use remains essential to avoid resistance. Dermatologists play a key role in the early diagnosis and treatment of STIs and must rely on a combination of clinical knowledge and rational use of antibiotics in prevention to develop effective long-term strategies.