What Could Cause My Daughter’s Wrist And Palm To Swell, Harden, And Feel Warm After Itching Without Injury Or Bite Marks?

My daughters left wrist is swollen no injury or visible markings from a bug bite either. She only noticed the swelling after she couldn t stop scratching. While looking at her wrist I noticed the palm of her right hand where she had also been scratching under the pinky finger wasslightly swollen, hard and warm.