I am glad that you posted your question
here and we will try our best to help you with this.
Vitamin B 12 also called as Cyanocobalamin and is usually administered
as injectables for those ho require it.
Like any other pharm
aceutical product, this may also cause unpred
ictable allergic reaction
s. I think this may be the reason
for the rash
that you have described.