Hi. Thanks for your query. Noted the history related to your grandson developing two large bumps on the right side of his forehead even though he definitely had not bumped himself. He was fine in himself and after a nights sleep the lumps had miraculously disappeared. Could you please suggest a possible cause for these lumps? Such large bumps which vanish on its own are due to angioneurotic edema. This is an allergic reaction to something in food or in the air, that can be found out on observation by the family members alone. You have to keep the dosage of antihistamine and oral steroids adjusted to his weigh at reach at home so that the next time it develops you can immediately give him medicines as this can be dangerous if they appear on the neck, in mouth or inside. This can not be due to hematoma as it could not vanish within a night.