Bitching about Itching
by Ed Dewke
posted <January 1998
One of the first things I was told about psoriasis—in fact, I was
told this on the occasion when I learned I was psoriatic—is that "itching
shouldn't be a problem." "Lesions don't generally itch," I was told,
"except in certain places or when they are irritated... Some flakers never
This does not reflect my reality. The very word, psoriasis,
derives from the Greek psora, meaning "itch." Why do you suppose the
condition was so-named? Because lesions don't generally itch?
I possess a marvelous book titled ABC's of the Human Body,
edited by Alma Guinness, published by Reader's Digest General Books, ©1987. From this
... [A]lthough itching can have an almost infinite number of causes, the reason it
develops remains the same. Certain small fibers in the top portion of the skin are moved
by a gentle, local stimulus, producing itching. The movement of these nerve endings is
transmitted to the nervous system. Scratching the itch can either remove the stimulus or
cause pain, which neutralizes the itching sensation in the spinal cord.
It does not take a genius to figure out why psoriasis lesions itch. For
one, the skin in which these nerves are imbedded is abnormal—thick, growing up to 14
times faster than normal, looked at under a microscope you see cells piled upon cells
helter skelter. Secondly, the upper most layer of psoriatic skin does not present a normal
skin surface to the environment, which means anything—a breeze, a covering fabric,
perhaps even heat from the sun—reacts differently. In the grossest of cases, when
flakers have scale breaking free, it can be like a thousand tiny protuberances jutting up
from the skin, begging to be "moved by a gentle, local stimulus," as it is
explained in the ABC's of the Human Body.
No, when you stop to consider it, the real mystery is why some
psoriasis lesions don't itch. It's reasonable to assume they all should itch.
But, in fact, even recalcitrant scratchers like myself have some
lesions that don't itch at all. And we can learn something from those itch-free lesions.
The ABC's of the Human Body goes on to explain that different
areas of the skin have more or less of the nerves that register an itching sensation.
Right there is probably one reason why some of our lesions itch less, or don't itch at
all: they erupt on areas of our skin with few "itch receptors." I've got some of
these on the sides of my torso and on the inner portions of my upper arms. Unless I
purposely inspect these dime-sized lesions, I can go weeks or months oblivious to their
existence—not even applying medication. Two things I have noticed about these
non-itchy lesions over the years: One, they never get really bad, meaning they
never cover over with thick, yellow-white, crusty scale; and two, they improve and nearly
fade away into invisibility as often, or more often, than the lesions I treat most
What does this suggest? What it suggests to me is that itching
and a lesion's worst behavior are associated, since those that don't itch never behave as
badly as those that do. Now I must consider: Is it the activity of these little nerve
cells that exacerbates lesion activity? Or is it the consequence—scratching?
According to the derms—even some of those very same ones who claim psoriasis lesions
don't generally itch!—treatment is more effective when the patient stops scratching.
My own case bears this out. Few would argue that scratching exacerbates psoriasis.
I tend to argue that scratching is a primary culprit in the crime against our
persons which is psoriasis.
Consider what scratching a psoriatic lesion accomplishes. At the very
least it scrapes off a layer (or several) of the dead psoriatic skin cells. At worst in
peels away scales that have some still living components. (In my private need for a
taxonomy I define a scale as a "flake" that is still connected to the
skin by some living tissue. I define a flake as a piece of entirely dead skin.)
Often, when we scratch scales away from a lesion there will be some bleeding. When this
occurs we are really damaging our skin. The aberrant immunological process that causes
psoriasis in the first place becomes suddenly appropriate. Remember, psoriasis is a
run-away regeneration of skin cells at up to 14 times faster than normal, a process
presumably called upon when and where skin is damaged and needs repair. Such skin regrowth
is appropriate at trauma sites—cuts, burns, scrapes, etc.—where scab needs to be
quickly replaced by new skin. Where it is inappropriate—that is, where no trauma
exists—this hyper regrowth creates a lesion.
Then there is the matter of gentle, harmless scratching. It is
reasonable to ask, "If I don't scratch away any living tissue I won't aggravate the
psoriasis—right?" Probably wrong, because there is probably no such thing as gentle,
harmless scratching. At least not without some comprehensive behavior modification.
Remember what the ABC's of the Human Body said: "Scratching the itch can
either remove the stimulus or cause pain, which neutralizes the itching sensation in the
spinal cord." Well, the stimulus for a psoriatic itch is internal. (It's not a bug
crawling on our skin or some other environmental "thing," which I think is
implied here by the phrase "remove the stimulus.") The lesion is not going to be
removed. So then, if we itch to satisfaction, what are we doing? We are itching until a
kind of pain is generated, which shuts off the itch sensation at the spinal cord. I would
argue that generating that kind of pain will most likely cause trauma to the skin, whether
or not we actually make ourselves bleed. Whatever the trauma from scratching may
become—heat, pressure, or torn skin—we are calling forth the same healing
response that has already run amok! We are begging our lesions to rebuild themselves!
My derm says, "When you want to scratch, rub on some lotion."
I took him seriously for awhile. I went through a lot of lotion and eventually learned
that a lesion saturated in emollient is like fine, soft topsoil: easily scooped away with
a shovel or fingernail. I caught myself literally hoeing rows in my larger
lesions—and bled a lot in the process. In my case, the advice to "rub on some
lotion" was an attempt at behavior modification that backfired. I'm sure not
scratching is a behavior that can be learned. I should be able to learn it. After
twenty-seven years of smoking I quit. But, in case you hadn't noticed, there's a lot of
help out there for people who want to quit smoking.
Where's the help to stop itching? No derm has ever looked me in the
face and said, "Okay, let's think about how we can tackle your itching problem."
Once or twice through the years a doc has reminded me that antihistamines diminish
itching. I have used them, sometimes, just for that purpose. But I have found the kind and
quantity of antihistamine I require to curb my itching puts me to sleep or at least turns
me into a zombie.
We've all heard of "itch cream." Topicals are out there to
tackle itching. I've never had much luck with them. Have you? Cortisone is touted as a
topical anti-itch drug, but again: Who with serious P has found it satisfactory? I believe
the "anti-itch" products were developed with something like mild poison Ivy, or
dinky insect bites in mind....
No, what we need is a topical pain killer that affects itching only,
but does so reliably and for a predictable length of time.
I can't remember the last research report I read (or read about) in
neurobiology, neuroscience or neurology, but I remember reading somewhere a fascinating
description of how nerve cells communicate: about the electro-chemical processes that
occur in synapses; about the fine differences between proteins that are like words in the
language of our nerves.... All of which sounds like knowledge presaging a major
development in biochemistry for controlling "nerve-speak." Is some such research
There should come a day when flakers don't have to give itching and
scratching a thought. A compound will be available as a prescript of its own—or
optionally as an added ingredient in your other topical flake medicine—that deadens
the urge to itch where it is applied to the skin. I wager 75% of anything I try to
palliate my flaking is going to work better when I stop scratching. -Ed Dewke