Hard lumps on head after botox which are still swollen after 3 days. Why did this happen? (Photo)

I have seen a similar reaction on a patient that was allergic to the preservative in the saline which is mixed with Botox at most offices. I proved it by injecting just the saline with preservative in the patient's arm and got the same reaction. Most docs use the saline w preservative because it is less painful. I think it's about 1-3% will be allergic. Allergy to Botox would be extremely rare. Infection is possible and would be associated with warmth, fever, and pain. They are treated differently so you need to go to the doctor to determine what is going on. 

I am not quite clear on the time course you describe.  Histamine-mediated allergies to Botox or the saline that is used to dilute the Botox can look like this but come and go quickly - like hives.  If you still have these bumps several days later and they are quite firm they may be deep bruises which will take several days to resolve.  I would consult a dermatologist who is experienced with both allergies and Botox.

I have been injecting Botox for approximately 20 years and have not seen the reaction that you are describing.  At first bush it looks like a possible allergic reaction to Botox.  I would return to your treating physician to determine the cause of your reaction.  It is always important to consult a board certified dermatologist with experience in cosmetics and Botox.  Please let me know what happens.