Rising Antimicrobial Resistance Demands New Strategies

“Antimicrobial resistance is not to be confused with antibacterial resistance. In fact, the major point of my talk was not just bacteria, but fungi, viruses, and ectoparasites can become resistant, and are becoming more resistant as time goes on,” said Ted Rosen, MD, in an interview at the 2025 Elevate-Derm Fall Conference.

Rosen, dermatologist, professor, and vice chair of dermatology at Baylor College of Medicine in Houston, Texas, presented “Antimicrobial Resistance and How to Deal With It” at Elevate-Derm Fall.¹ In an interview with Dermatology Times, Rosen discussed top tips from his session for clinicians, as well as the importance of collaboration among dermatology clinicians.

Antimicrobial Resistance

Rosen first discussed the expanding scope of antimicrobial resistance (AMR) across bacterial, fungal, viral, and parasitic pathogens. He emphasized that resistance patterns now extend well beyond conventional bacterial concerns and require localized awareness, diagnostic support, and shared clinical judgment across the dermatology care team.

According to Rosen, regional variability plays a critical role in bacterial management. While global mupirocin resistance in impetigo remains around 8% to 14%, certain US communities report rates approaching 40% to 60%. In those settings, the agent remains safe but can no longer be considered reliably effective. He urged dermatology clinicians to remain familiar with their community’s patterns and to recognize when treatment failures warrant culture and susceptibility confirmation.

Fungal resistance is emerging as particularly consequential. Rosen highlighted rising terbinafine- and itraconazole-resistant Trichophyton isolates, including T. rubrum, T. indotineae, and several saprophytic species. Because antifungal susceptibility testing is more complex, he recommended identifying a laboratory capable of performing this work and incorporating culture-based decision-making when empiric therapies fail.

Parasitic infections present parallel challenges. Approximately 15% of scabies cases now exhibit resistance to permethrin, ivermectin, or both. Rosen advised clinicians to reconsider older sulfur-based regimens or adopt spinosad, which, although approved for head lice, offers an 80% to 90% cure rate for scabies with a single overnight application. He added that resistance among head lice to over-the-counter pyrethroids is nearly universal, and that constraints in the availability of malathion and ivermectin leave spinosad—and occlusive therapies such as dimethicone or even Cetaphil-based asphyxiation approaches—as primary options.

Viral resistance is also increasing, particularly among immunocompromised patients with HSV-1 or HSV-2 who fail acyclovir-class therapies. Rosen previewed the anticipated arrival of pritelivir mesylate, a helicase–primase inhibitor expected within the next year. Early access is possible under special circumstances for patients over 16 years with severe, treatment-refractory disease.²

Clinic Collaboration

Rosen concluded his interview by stressing the importance of shared learning and unified therapeutic standards among physicians, NPs, and PAs. With dermatology managing only a fraction of the national skin disease burden, he stressed that consistent education across all frontline clinicians is essential to addressing AMR effectively.

References

1. Rosen T. Antimicrobial resistance and how to deal with it. Presented at: 2025 Elevate-Derm Fall Conference; November 12-16, 2025; Tampa, FL.
2. Aicuris announces pritelivir met primary endpoint in immunocompromised herpes simplex virus-infected patients in phase 3 pivotal trial. News release. Aicuris. October 16, 2025. Accessed November 20, 2025. https://www.aicuris.com/press-release/aicuris-announces-pritelivir-met-primary-endpoint-in-immunocompromised-herpes-simplex-virus-infected-patients-in-phase-3-pivotal-trial/