My son is ten years old and has been swimming alot. he went to the doctor and has no ear infection, but earlobe hurts and his a little puffy. ?

Insect bite ?: This tissue is somewhat sensitive to any insect bite that would be incidental to his swimming. If the area is just puffy,pink and uncomfortable to touch a simple bite would be the most common cause.A pustule,tense tissue or draining site might warrant a visit, otherwise it should fade over a few days.

Earlobe pain: Earlobe pain and swelling can be due to: allergy (put cold ice on it); insect bite (mosquito, spider, tick, etc) irritation from chemicals/irritants; infection (usually swollen & red & painful to touch); if MD did not see an infection, likely one of other causes.