$Unique_ID{BRK01305}
$Pretitle{Skin and Subcutaneous Tissue, Special Procedures and Laboratory
Tests}
$Title{Can You Tell Me About the Magic Light Used to Diagnose Skin Rash?}
$Subject{skin rash diagnosis Wood's Light}
$Volume{L-20, P-20}
$Log{}

Copyright (c) 1991   Tribune Media Services, Inc.


Can You Tell Me About the Magic Light Used to Diagnose Skin Rash?


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QUESTION:  Although many doctors were unable to diagnose my very peculiar skin
rash, I finally met a doctor with a new gimmick that did the trick.  He took
me in a dark room, and used a special light on me, that made the rash glow in
the dark.  Within a few seconds he had the answer I had spent months looking
for.  Now, can you tell me about that magic light?  I am afraid that my doctor
was better at using the lamp than explaining how it works, so it is up to you.

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ANSWER:  The name of the "magic lamp" is a Wood's Light that produces black
light that is invisible to the eye.  Using a mercury vapor source, the light
passes through a special nickel-chromium oxide silica filter, that transmits
long wave ultraviolet radiation.  Certain materials as well as fungi and
bacteria (including Pseudomonas) "fluoresce" or glow under this light, and can
be easily detected.  The same light is responsible for many special effects
used in theatrical productions.  This technique is useful in recognizing the
differences in skin pigmentation, as well as pigmented lesions.  Many of the
organisms fluoresce in different colors with tinea versicolor showing up a
golden yellow, and pseudomonas ranging from aqua-green to blue.  The screening
works best if the patient has avoided bathing for 24 hours, and when the room
is totally dark.  Once the Wood's light has detected the problem other tests
may be used to clinch the diagnosis.
ÿ
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The material contained here is "FOR INFORMATION ONLY" and should not replace 
the counsel and advice of your personal physician.  Promptly consulting your 
doctor is the best path to a quick and successful resolution of any medical 
problem.
