I had dermal fillers (.5ml) in my cheeks and fainted. Could this have been an allergic reaction?

Thank you for a great question.  Hope you are feeling better and love your filler results. You simply got too nervous and fainted as your nervous system got too excited.  It's not uncommon and you should not feel bad about it.  You should just warn your providers when you get your next injection so they can be better prepared and have a glass of water near by and an ice pack.  Next time it will be easier as you already know what to expect.  Hope this helps. Best, Dr.Avaliani

No, this is unlikely an allergic reaction, but does sound like a vasovagal reaction. It is not typical to stop breathing. I recommend following up with your Doctor. Best, Dr. Emer

It sounds like what you experienced was due to the procedure itself and not due to an allergic reaction. You probably had what is called a Vaso vagal reaction which occurs during times of increased anxiety and fear. Only thing that can s a bit unusual is that you stated you stopped breathing which is unusual in these kind of cases. Please follow up with your primary care physician. 

The episode that you had is not an uncommon.  The condition is called Neurocardiogenic syncope(previously called and better known as Vasovagal Syncope).  It's estimated that about 25% of the population has this and there are certain triggers(blood, needles, car accidents, etc...)  We don't really understand why but in some people certain events will result in an automatic and uncontrollable response to the nervous system that drops the heart rate and blood pressure down to the point where there is such a small amount of blood flow to the brain that you faint.  It's extremely alarming to patients, but usually harmless.  I would definitely let your provider(s) know this happened to you so they can be prepared should it happen again.

Yes, your fainting is most likely a simple vasovagal type reaction to the procedure.  It can happen from the simplest of procedures and is not unusual to occur just after the procedure is complete.  Although I would be comfortable performing procedures on you in the future it will be very important for your physicians to be aware of this incident.  And, since I do not know your full medical history it may be worth touching base with your primary physician.