A patient presenting with severe genital irritation and lesions tests negative for common STD pathogens. What should be the next line of testing?

In this scenario, the patient's severe genital irritation and lesions, coupled with a negative test result for common STD pathogens, suggest that an underlying viral infection could be responsible for the symptoms. Herpes simplex virus (HSV) is a well-known cause of genital lesions and can often be overlooked if standard tests targeting other bacterial or parasitic infections are performed first.

Testing for herpes simplex is particularly warranted because it can produce significant genital irritation and lesions resembling other STDs. Furthermore, the initial negative results could indicate that a less commonly tested infection, such as HSV, may be present. Ignoring the possibility of herpes could lead to ongoing discomfort and complications for the patient, making it a critical next step in diagnosis and treatment.

Other testing options, such as darkfield examination, typically focus on detecting syphilis, which is not in line with the patient's symptoms and unlikely given the context of negative results for usual STDs. Similarly, testing for Trichomonas or Group B streptococci would not be the most logical next steps, as Trichomonas usually presents with distinct symptoms and Group B strep is more associated with pregnancy-related infections rather than isolated genital lesions in this clinical context. Thus, focusing on herpes simplex virus testing is the most appropriate