Welcome and thanks for posting your query to HCM.
After reading your query it is too early to make any exact or nearest possible diagnosis. Just keep a close watch over the area, if it gets more red or darkened or any itching or pain appears on the swelling then you can again give a feed back and take necessary advice. Till that time you can apply simple calamine
lotion over the area. DO not expose yourself to direct sunlight.
With good health wishes
Dr. Sanjay Kumar Kanodia