Final answer:
The 22-year-old woman is diagnosed with a urinary tract infection (UTI) based on her symptoms. Further actions include obtaining a urine culture and prescribing antibiotics.
Step-by-step explanation:
The diagnosis for the 22-year-old woman in the question is a urinary tract infection (UTI) caused by a bacterial infection. The critical clinical features that lead to this diagnosis are the slight fever, frequent urination with burning sensation, vaginal discharge, and the small lesion on the labia. Further actions that must be taken include obtaining a urine culture to determine the specific bacteria causing the infection and its antibiotic susceptibility. The physician should also prescribe appropriate antibiotics to treat the UTI.