Oh ok. The itch is outside, not inside? If its inside, it could be from the chlamydia.
Have you notified your partner? You should. Untreated chlamydia can cause all kinds of serious long term problems, especially for women. Its the kind thing to do, and she probably doesn't know she has it - most women don't get symptoms.
Aj
The itch began a week after intercourse. I just took the dose yesterday so I don't think it had any effect on the itch.
So the itch came after the antibiotics? It could be a mild yeast infection or jock itch, which is really common after antibiotic use.
Follow up with your doctor.
Aj