Leprosy
mailing list – May 4th, 2005
Ccn: all.
Ref.: ball point pen method for sensory testing: a `low
sensitivity` test.
From: P Narasimha Rao,
Hyderabad
,
India
.
Dear
Salvatore,
Greetings. In continuation of arguments put forward by Dr
Ben Naafs
I have the following to say regarding the ball point pen examination
for sensory loss.
New clinical method: ball point pen testing for sensations.
All the field workers were advised by WHO and other leprosy
authorities to test the cutaneous sensation in leprosy patients by pen
or ball point pen. Hitherto the skin sensations were being
tested by pin/needle in most areas and either by wisp of cotton
or by graded nylon filaments in areas such as face and it was a
part of standard method of clinical examination and teaching to
students of leprosy.
The new
method of testing cutaneous sensation by tip of a pen is being
followed all over
India
/other countries by most leprosy workers from the year 2002-2003.
Reason given: needles can transmit HIV.
Refer to the
WHO publication: Guide to eliminate leprosy as a Public Health Problem
(see PAOG
website - How to Test for Sensory Loss –
Take a
pointed object such as a pen…
Lightly touch
the skin with the pen...
Lightly touch
the centre of the most prominent skin patch and ask the patient to
point to where they felt the pen…
Repeat the
procedure on normal skin and on the same patch again...
If the person
feels nothing on the skin patch, it is leprosy. Start treatment
immediately. … So on it explains.)
Let's examine the facts: ball point pens test which sensation?
Fine touch: NO.
Pain: NO.
Crude touch: Yes
Pressure: May be
It is widely
known that the important sensations to be tested in leprosy patient
are thermal sensation, pain and fine touch, in that order. Crude touch
and pressure are not the sensations to be lost early in a patient with
leprosy. It is very important to test for fine touch sensation in
areas such as face to arrive at correct diagnosis.
If the
argument of avoiding needles in testing cutaneous sensation is true,
better options are available. It is widely known that the risk of
transmitting HIV is much less with solid needles compared to bored
needles. Why not use solid needles if it is only prevent the
transmission of HIV? Best option is to use disposable needles / pins
as they do significantly add to the expenditure of the programme. (Even al-pins
can be used in resource poor settings as they are economical and
available widely.)
Result of ball point pen testing:
Ball point pen testing of sensation is a `low sensitivity` test. And
any low sensitivity test is known to have more `False negatives`
which otherwise means that new cases are being missed. This directly
affects the new case detection especially in areas such as face. Is
this is one way of bringing down new case detection rate (NCDR)?
Narasimha Rao P
Hyderabad,
India
