Final answer:
The nurse should first suspect genital herpes as the problem based on the patient's description of itchy lesions on her vulva that have recently burst. Genital herpes is an STI caused by the herpes virus.
Step-by-step explanation:
Based on the patient's description of itchy lesions on her vulva that have recently burst, the nurse should first suspect genital herpes as the problem. Genital herpes is an STI caused by the herpes virus, which can cause the development of infectious vesicles.