Over the past four years my Calico/Tabby cat has been exhibiting a similar
behavior. She has been seen by 4 different vets and non of them have been
able to diagnose or solve the problem.

Despite the cortisone shot, a change in diet in case of allergies and blah
blah blah - she continues to have issues.

Something is really wrong with your cat. She's incredibly stressed, either
because someone is abusing her or because she is suffering physically.
Also, flea treatments are poison to cats, just as pesticides are poison to
you, so avoid them unless you see fleas.  No animal should be licking fur on
which flea treatment has been sprayed no matter how safe the product CLAIMS
it is.

Avoid flea collars as well.  One of my cats developed throat cancer because
of that.   The chemical gets absorbed right into the skin.  If you wouldn't
put such a collar on your baby, don't put it on your cat, no matter how safe
the label says it is.

I suspect most of all that your cat is allergic to the flea spray.   It's
making her skin itch and is driving her crazy.   Give her a good shampoo
with mild shampoo designed ONLY for cats to get that poisonous stuff out of
her fur, and brush her fur very softly every day (from BEHIND her head)
slowly and softly (without pulling or applying pressure) in a way that will
relax her.  It will also help stimulate her circulation and give her
healthier fur.

If your cat is grey coloured and has long hair, these cats are wonderful,
shy and very dainty pets but they're also very sensitive and easily
stressed.   They like a lot of quiet time.  Cats also need at least one
quiet spot in the house where they can be ASSURED that no one will ever
bother them if they need private time to sleep or just relax.  If she
doesn't have such a spot, create one for her that you know she will love.
Also, don't play loud rock or other music around animals.  Their ears are
very sensitive and this both hurts their ears and stresses the animals.

If this habit continues after you have tried all of these things (could take
a month and a couple of washes two weeks apart before the spray is removed
from the hair), then your cat may be suffering from emotional problems just
as humans do.  She may also be suffering from some form of exzema or other
skin condition so she should be checked out by a vet who may be able to
offer treatment for it.

She could even be allergic to her cat litter so you might want to try
switching brands and making sure it's clean.

Something could also be lacking in her diet, particularly healthy fish oils,
so you might want to give her boneless fish a couple of times a week, or
even a small finger-tipped bit of butter a couple of times a week.  (That
should help with depression as well).

You might also want to buy her some good quality cat food such as Science
Diet for a couple of months.  It may be expensive, but all healthy food is,
as it does do wonders for a cat's health.

Don't get too carried away with comments from drug companies.  Prozac is a
dangerous drug that causes great harm to the liver eventually.  Often if
cat's suffer from anxiety it's because of one of the many reasons I
discussed in the previous message.  Children who tease animals or who won't
allow them a special spot for peace and quiet can also create extreme
anxiety.

Oh dont worry...she's coming along well on her diet.  When we got her, she
was 24 lbs.  She's very vocal and the old owners used food to make her quiet
instead of the attention we give her.  It's amazing how much exercise they
get when they chase a laser beam.