This is a condition which will heal on it's own. You should place an ice pack over the area so that the swelling reduces, you can do this 3-4 times a day. If there is any itching as such you will require an antihistamine. If the condition persists or worsens visit the ER at the earliest.
Next Steps
Follow the steps as advised
Health Tips
If condition persists or worsens visit the ER at the earliest