People who suffer itching with no clear cause may have defects in their immune systems that havent been recognized. In a small study of patients who struggle with itching but have no known cause, researchers from the Center for the Study of Itch at Washington University School of Medicine in St. Louis identified several immune system irregularities that may underlie the urge to scratch. The patients suffer from what doctors call chronic idiopathic pruritis. Studying blood samples and skin biopsies, the researchers have found some very unusual things in the immune systems of these patients.
SOME PEOPLE SUFFER HAVE BAD PROBLEMS WITH ITCHING BECAUSE THEY HAVE A RASH OR SOME OTHER SKIN CONDITION. BUT OTHERS HAVE ITCHING PROBLEMS WITH NO KNOWN CAUSE. NOW RESEARCHERS FROM THE CENTER FOR THE STUDY OF ITCH AT WASHINGTON UNIVERSITY SCHOOL OF MEDICINE IN ST. LOUIS HAVE IDENTIFIED DEFECTS IN THE IMMUNE SYSTEMS OF SOME PATIENTS WITH THAT TYPE OF ITCHING THAT MAY UNDERLIE THE URGE TO SCRATCH. JIM DRYDEN HAS MORE
ALTHOUGH ITS RELATIVELY UNCOMMON, A CONDITION CALLED CHRONIC IDIOPATHIC PRURITIS IS ONE OF THE MOST DIFFICULT TYPES OF ITCHING TO TREAT BECAUSE THE BEST TARGET FOR THERAPY REMAINS UNKNOWN. WHEN A PERSON WITH AN ITCHY RASH GOES TO THE DERMATOLOGIST, THE DOCTOR OFTEN ORDERS A SKIN BIOPSY TO SEE WHATS UP. BUT IN PATIENTS WITH ITCHING WITHOUT A KNOWN CAUSE, THERES NOTHING TO BIOPSY. WASHINGTON UNIVERSITY DERMATOLOGIST BRAIN KIM SAYS SOMETIMES PEOPLE WONDER IF THE ITCHING IS ALL IN THEIR HEADS.
(act) :14 o/c our mission
It is often viewed as a wastebasket term in that theres
nothing really wrong with these patients. But, you know, if it
was simply, you know, a psychiatric disorder or something not
otherwise specified, we should try to figure out whats going on.
And thats, really, what weve taken as our mission.
KIM RUNS A CLINIC FOR PEOPLE WITH CHRONIC ITCHING. AMY XU, A MEDICAL STUDENT WHO WORKS IN KIMS LAB, SAYS SOME OF THE PATIENTS HAVE ECZEMA OR SOME OTHER KNOWN SKIN CONDITION, BUT OTHERS DONT.
(act) :16 o/c their itch
So these patients have itch that is of unknown origin,
meaning that we do a whole bunch of lab tests, and we get
a chest X-ray and other things on them and find that they
really dont have any primary, like, skin conditions, or
other medical conditions, that could be causing their itch.
XU IS THE FIRST AUTHOR ON A NEW STUDY FROM KIMS LAB THAT ANALYZED SKIN AND BLOOD SAMPLES FROM PATIENTS WITH ITCHING, BUT NO KNOWN CAUSE, TO SEE WHETHER THEY COULD FIND ANY SIMILARITIES BETWEEN THE PATIENTS. KIM SAYS THEY DID FIND ELEVATED LEVELS OF IMMUNE CELLS, CALLED EOSINOPHILS, IN THOSE SAMPLES. EOSINOPHILS USUALLY ARE MARKERS OF ALLERGIC INFLAMMATION.
(act) :13 o/c the itch
The thought is, could that just be secondary to scratching?
Its possible, but then you look deeper in the blood, and then
you see profound immune defects in the blood. There is this
immune dysregulation, and its very likely that this immune
dysregulation is contributing to the chronicity of the itch.
THE STUDY LOOKED ONLY AT A SMALL SAMPLE A PATIENTS. THERE WERE 4 IN THIS INITIAL STUDY. BUT KIM FOUND THAT CERTAIN IMMUNE SYSTEM DEFECTS WERE COMMON IN 3 OF THEM.
(act) :21 o/c a rash
Three of them have elevated IgE, which is a marker of allergic
inflammation. Three of them have elevated eosinophils, which is
another marker of allergic inflammation. Whats unique about them
is that they dont have a history of atopic dermatitis or other
allergic disorders, and the other thing thats common to all of them
is they typically dont have a rash.
KIM SAYS THE EARLY FINDINGS SUGGEST THAT WHEN IT COMES TO THIS SORT OF UNEXPLAINED CHRONIC ITCHING, IT ISNT REALLY ALL IN THEIR HEADS.
(act) :21 o/c for instance
Weve now been more routinely doing these clinical tests to
identify whats going on in these patients, and, in fact, we
have many more patients; and what were finding out is that the
immune dysfunction is now stratifying across different defects.
Some patients will have such profound defects that weve actually
sent them to our colleagues in allergy and immunology, for instance.
KIMS LAB IS NOW WORKING TO MAKE MOUSE MODELS THAT HAVE SOME OF THE SAME UNDERLYING IMMUNE DEFECTS IN ORDER TO DEVELOP BETTER TREATMENTS. HIS TEAM REPORTS ON THOSE DEFECTS IN THE JOURNAL OF THE AMERICAN ACADEMY OF DERMATOLOGY. IM JIM DRYDEN…