The California Department of Public Health (CDPH) issued a health advisory yesterday to inform health care providers that the first known United States (U.S.) case of sexually transmitted Trichophyton mentagrophytes genotype VII (TMVII) was reported in June 2024 in a patient who had recently traveled to California. TMVII is a rare dermatophyte (e.g., ringworm or tinea) infection that causes highly inflammatory, painful, and persistent lesions, often affecting the anogenital or perioral areas, and may require weeks of oral antifungal treatment. Prior to this case, sexual transmission of TMVII had been reported in France, primarily among men who have sex with men (MSM), and among other persons in European countries returning from Southeast Asia who had engaged in sex tourism. Given the novelty of sexually transmitted dermatophyte infections and the potential for local spread in the United States, CDPH would like to inform clinicians of TMVII as a potential emerging public health concern and provide guidance on the clinical recognition, diagnosis, and treatment of patients who are suspected to have this infection.