Is There Possible for Any Side Effects from Botox Injections (In the Armpits) Which Have Been Applied 1 Year Ago?

Are your bumps cysts, boils (infected hair follicles) unrelated to the Botox you had?  Is there a possibility that your hyperhidrosis (increased sweating) has resumed and is causing some skin reaction?  See a dermatologist to evaluate your condition.

12 units of BOTOX is a very small treatment for hyperhydrosis.  For the swelling that you are experiencing, I would recommend that you see your physician if the process is getting worse or reoccurs.  This can represent a skin infection.  

Hyperhidrosia, or excessive sweating is an extremely common problem.  Some reports show that it may affect up to 3% of the population.  Injections with Botox are quite effective in alleviating this problem.  One of the downsides though is that the results usually one last up to 8 or 9 months.  If you are having problems, and its been more than a year since your last injections, it's unlikely that the Botox are to blame.  It is probably best for your to discuss this in person with your dermatologist or plastic surgeon.  Your account makes an infectious cause much more likely.

The effects of Botox to the underarms can last up to 6 months, it is highly unlikely that your Botox is currently causing these effects 1 year after injections. I recommend an in-person examination with your physician for further investigation.
I've created a video that reviews treating underarm sweating with botox. I hope this is helpful in your research! 

I inject Botox in the underarms more than 10 times a week and I have never seen this or heard of this problem. We typically give 50-100 injections to deliver the amount of Botox and I do not think that your lumps, bumps are related to Botox injections. Hydradenitis ? Seek a dermatologst to help you out.