The diagnosis of mucocutaneous HSV may be made on clinical grounds alone in the majority of cases. Vesicular fluid should be swabbed to confirm the presence of HSV using polymerase chain reaction (PCR) or nucleic acid amplification testing (NAAT), and exclude other alternate or concurrent viral pathogens (including varicella, discussed below) as well as bacterial co-infection. (18)  In cases of treatment-refractory HSV infection, viral culture or genotyping of swabbed vesicles may be required for resistance analysis (19). In cases of atypical ulcerative or verrucous lesions, biopsy may be required. (17). It should be noted that HSV serology has low sensitivity in diagnosing acute infection and has limited clinical utility (20).