Hi thanks for your question.
Four year old traumatic lump appears on taking acetaminophen
and alcohol and disappears after that. Pharmacodynamics and pharmacokinetic (Absorption, action and disposal of a drug)of Alcohol and acetaminophen cannot explain appearing and disappearing of this lump. Sinus infection
also cannot cause lump on forehead. Most probably this lump is in your mind rather than on forehead, as your CT scan
is normal. I would suggest you to get yourself examined by general surgeon
, when you think this lump is on your forehead. He/she can explain you what is exactly this lump is ? And why it appears after alcohol or acetaminophen.
Hope this answers your question.