Key Takeaways Ear swelling can be caused by infections, trauma, or allergic reactions. Cold or warm compresses can help reduce pain and swelling in the ear. Perichondritis, an infection of the ear cartilage, may require antibiotics or surgery. A swollen ear occurs when fluid builds up in the tissues in or around your ear. Ear swelling can be caused by ear piercing, trauma to the area (such as getting hit by a ball), an infection, and certain medical conditions.