At a Loss for Words

This does not happen to me often.
There is a lady who posts - a lot - on the support group.  She is very knowledgeable and seems intelligent.
She is also abrasive, condescending, insulting, assumptive and arrogant. (I think that about covers it)
I had posted a reply regarding pain meds and stated that addiction is a real problem for people with chronic pain.  I based my statement on what I have learned from my late father, a psychologist who specialized in addiction and my sister-in-law who holds a Phd in pharmacology, runs a coumaden clinic in Oak Harbor and teaches at the University of Washington.
She made a reply directly after mine with the opening statement "Please read my post. Addiction is NOT a problem with people who actually are in pain."
I didn't read her previous posts, I rarely do, because of the afore mentioned personality traits.
It is hard to not be offended by such an overbearing, offensive person.
I would love to think of something to say that would shut her down.