Actually, that's a big focus for research and new treatments and it can be used to treat certain common and troublesome skin conditions.  First, you make the patient allergic to something they would not normally encounter in nature.  You don't make them allergic to poison ivy -- because they may encounter that from time to time.  But you can make them allergic to products known to dermatologists as squaric acid or another called DPC.  Fortunately, these chemicals are not found in our everyday environment, because contact with them on human skin renders almost everyone so allergic to them that a fierce, sometimes blistering rash follows.  Now THAT'S and immune response!

How to make use of this immune response?  Some common, viral warts are remarkably resistant to treatment, defying all forms of repeated medication and destruction.  When all else fails some dermatologists take squaric acid or DPC, paint it on patients to make them allergic to it, and than later put it on the wart.  Wow -- the ensuing reaction can sometimes blast that wart away, apparently by harnessing that otherwise nasty immune response.  This same concept is sometimes tried on a common hair disorder called alopecia areata, patchy hair loss considered auto-immune -- caused by the body's own immune system -- in origin.

Immunotherapy -- "p" not for "perfect", but for "promising"; using the body's own immune system to treat itself.  For a copy of this script visit our web site, speakingofhealth.com.  Speaking of Heath, I'm Dr. Steven Andrew Davis, for CBS News.

Ref:  Clinics in Dermatology. Vol 20, No. 5, Sept/Oct 2002, pgs. 515-521