Dear Sir/Madam, Thanks for seeking help on your issue; I have gone through your symptoms, and in my opinion, the swelling you were having was a haematoma, which means collection of blood. that could have occurred due to rupture of vein or small vessels on the scalp. its spread and diffused on the face and will vanish by body self clearing mechanism in a few days, don t be too concerned I hope I have been able to provide you with a satisfactory solution, if you want to clear any doubts about my opinion, feel free to contact. Special note- Any medication prescribed needs to be taken after consultation with your personal doctor only. Thanks Dr. Narender Saini