It sounds like this is a rather toxic person. After dealing myself with a very toxic coworker, I found this article that helps explain a lot when it comes to what a toxic person is and how to deal with them.
Just note that it does not specifically explain "what to do with this person in this case", as of course each case is unique. In your case, I recommend reading that article as it will hopefully help you understand why others are saying to basically ignore it. What follow's is everything but the stuff about effects of stress:
Toxic people defy logic. Some are blissfully unaware of the negative
impact that they have on those around them, and others seem to derive
satisfaction from creating chaos and pushing other people’s buttons.
Either way, they create unnecessary complexity, strife, and worst of
all stress. Whether it’s negativity, cruelty, the victim syndrome, or
just plain craziness, toxic people drive your brain into a
stressed-out state that should be avoided at all costs.
While I’ve run across numerous effective strategies that successful
people employ when dealing with toxic people, what follows are twelve
of the best. To deal with toxic people effectively, you need an
approach that enables you, across the board, to control what you can
and eliminate what you can’t. The important thing to remember is that
you are in control of far more than you realize.
- They Set Limits (Especially with Complainers)
Complainers and negative people are bad news because they wallow in their problems and fail to focus on solutions. They want people to join their pity party so that they can feel better about themselves. People often
feel
pressure to listen to complainers because they don’t want to be seen
as callous or rude, but there’s a fine line between lending a
sympathetic ear and getting sucked into their negative emotional
spiral.
You can avoid this only by setting limits and distancing yourself when
necessary. Think of it this way: if the complainer were smoking, would
you sit there all afternoon inhaling the second-hand smoke? You’d
distance yourself, and you should do the same with complainers. A
great way to set limits is to ask complainers how they intend to fix
the problem. They will either quiet down or redirect the conversation
in a productive direction.
- They Don’t Die in the Fight
Successful people know how important it is to live to fight another day, especially when your foe is a toxic
individual. In conflict, unchecked emotion makes you dig your heels in
and fight the kind of battle that can leave you severely damaged. When
you read and respond to your emotions, you’re able to choose your
battles wisely and only stand your ground when the time is right.
- They Rise Above
Toxic people drive you crazy because their behavior is so irrational. Make no mistake about it; their behavior truly goes
against reason. So why do you allow yourself to respond to them
emotionally and get sucked into the mix?
The more irrational and off-base someone is, the easier it should be
for you to remove yourself from their traps. Quit trying to beat them
at their own game. Distance yourself from them emotionally and
approach your interactions like they’re a science project (or you’re
their shrink, if you prefer the analogy). You don’t need to respond to
the emotional chaos—only the facts.
- They Stay Aware of Their Emotions
Maintaining an emotional distance requires awareness. You can’t stop someone from pushing your buttons
if you don’t recognize when it’s happening. Sometimes you’ll find
yourself in situations where you’ll need to regroup and choose the
best way forward. This is fine and you shouldn’t be afraid to buy
yourself some time to do so.
Think of it this way—if a mentally unstable person approaches you on
the street and tells you he’s John F. Kennedy, you’re unlikely to set
him straight. When you find yourself with a coworker who is engaged in
similarly derailed thinking, sometimes it’s best to just smile and
nod. If you’re going to have to straighten them out, it’s better to
give yourself some time to plan the best way to go about it.
- They Establish Boundaries
This is the area where most people tend to sell themselves short. They feel like because they work or live
with someone, they have no way to control the chaos. This couldn’t be
further from the truth. Once you’ve found your way to Rise Above a
person, you’ll begin to find their behavior more predictable and
easier to understand. This will equip you to think rationally about
when and where you have to put up with them and when you don’t. For
example, even if you work with someone closely on a project team, that
doesn’t mean that you need to have the same level of one-on-one
interaction with them that you have with other team members.
You can establish a boundary, but you’ll have to do so consciously and
proactively. If you let things happen naturally, you are bound to find
yourself constantly embroiled in difficult conversations. If you set
boundaries and decide when and where you’ll engage a difficult person,
you can control much of the chaos. The only trick is to stick to your
guns and keep boundaries in place when the person tries to encroach
upon them, which they will.
- They Won’t Let Anyone Limit Their Joy
When your sense of pleasure and satisfaction are derived from the opinions of other people, you
are no longer the master of your own happiness. When emotionally
intelligent people feel good about something that they’ve done, they
won’t let anyone’s opinions or snide remarks take that away from them.
While it’s impossible to turn off your reactions to what others think
of you, you don’t have to compare yourself to others, and you can
always take people’s opinions with a grain of salt. That way, no
matter what toxic people are thinking or doing, your self-worth comes
from within. Regardless of what people think of you at any particular
moment, one thing is certain—you’re never as good or bad as they say
you are.
- They Don’t Focus on Problems—Only Solutions
Where you focus your attention determines your emotional state. When you fixate on the
problems you’re facing, you create and prolong negative emotions and
stress. When you focus on actions to better yourself and your
circumstances, you create a sense of personal efficacy that produces
positive emotions and reduces stress.
When it comes to toxic people, fixating on how crazy and difficult
they are gives them power over you. Quit thinking about how troubling
your difficult person is, and focus instead on how you’re going to go
about handling them. This makes you more effective by putting you in
control, and it will reduce the amount of stress you experience when
interacting with them.
- They Don’t Forget
Emotionally intelligent people are quick to forgive, but that doesn’t mean that they forget. Forgiveness requires
letting go of what’s happened so that you can move on. It doesn’t mean
you’ll give a wrongdoer another chance. Successful people are
unwilling to be bogged down unnecessarily by others’ mistakes, so they
let them go quickly and are assertive in protecting themselves from
future harm.
- They Squash Negative Self-Talk
Sometimes you absorb the negativity of other people. There’s nothing wrong with feeling bad about how
someone is treating you, but your self-talk (the thoughts you have
about your feelings) can either intensify the negativity or help you
move past it. Negative self-talk is unrealistic, unnecessary, and
self-defeating. It sends you into a downward emotional spiral that is
difficult to pull out of. You should avoid negative self-talk at all
costs.
- They Limit Their Caffeine Intake
Drinking caffeine triggers the release of adrenaline. Adrenaline is the source of the
“fight-or-flight” response, a survival mechanism that forces you to
stand up and fight or run for the hills when faced with a threat. The
fight-or-flight mechanism sidesteps rational thinking in favor of a
faster response. This is great when a bear is chasing you, but not so
great when you’re surprised in the hallway by an angry coworker.
- They Get Some Sleep
I’ve beaten this one to death over the years and can’t say enough about the importance of sleep to increasing your
emotional intelligence and managing your stress levels. When you
sleep, your brain literally recharges, shuffling through the day’s
memories and storing or discarding them (which causes dreams), so that
you wake up alert and clear-headed. Your self-control, attention, and
memory are all reduced when you don’t get enough—or the right kind—of
sleep. Sleep deprivation raises stress hormone levels on its own, even
without a stressor present. A good night’s sleep makes you more
positive, creative, and proactive in your approach to toxic people,
giving you the perspective you need to deal effectively with them.
- They Use Their Support System
It’s tempting, yet entirely ineffective, to attempt tackling everything by yourself. To deal with
toxic people, you need to recognize the weaknesses in your approach to
them. This means tapping into your support system to gain perspective
on a challenging person. Everyone has someone at work and/or outside
work who is on their team, rooting for them, and ready to help them
get the best from a difficult situation. Identify these individuals in
your life and make an effort to seek their insight and assistance when
you need it. Something as simple as explaining the situation can lead
to a new perspective. Most of the time, other people can see a
solution that you can’t because they are not as emotionally invested
in the situation.
Bringing It All Together
Before you get this system to work
brilliantly, you’re going to have to pass some tests. Most of the
time, you will find yourself tested by touchy interactions with
problem people. Thankfully, the plasticity of the brain allows it to
mold and change as you practice new behaviors, even when you fail.
Implementing these healthy, stress-relieving techniques for dealing
with difficult people will train your brain to handle stress more
effectively and decrease the likelihood of ill effects.