Try to keep water out of your ears when you wash your hair. Don't swim or play other water sports. If you're on a swim team, ask your doctor before you return to swimming. Don't put anything except the prescribed medicine in your ears. Scratching and rubbing will only make OE worse.
Symptoms are usually much better in three days.
They should be completely gone in 10 days. If you're not better by then, call your doctor. The best way to prevent OE is to keep the ear canal's natural defenses against infection working well. This can damage or irritate the skin. If your ears itch a lot, see your doctor.