Dengue Fever - now we have a vaccine!
Many people were under the impression
that Dengue is a mild illness, caused by a mosquito bite. However, with the
Thai TV actor ending up in intensive care with Dengue Hemorrhagic Fever,
this has brought home the realities of this disease.
The female Aedes aegypti mosquito,
which carries the Dengue virus, is the culprit. Dengue fever is endemic
locally and the change in the weather is partly to blame (not to be confused
with “climate change”, by the way).
Since the beginning of this year,
dengue fever is reported to have been seen in 14,000 people. The Disease
Control Department says the rainy season each year is usually the breeding
period for the dengue virus, and it has certainly rained recently.
So, despite my previous pleas (and
those of the Public Health Department), Dengue Fever and its potentially
fatal variant, Dengue Hemorrhagic Fever (DHF) is still with us. The latest
information has now prompted me to repeat my advice on this subject. If you
remember reading about it before, I apologize, but the subject matter is
very important. This is an important ailment, which can be avoided.
However, first you should understand a
little more about Dengue and its history. It was first described in 1780 by
a Benjamin Rush in Philadelphia (so it didn’t start here) when the name
Break Bone Fever was applied, with the symptoms of pain in the bones and
rise in temperature. The name “Dengue” came in 1828 during an epidemic in
Cuba. The new name was a Spanish attempt at a Swahili phrase “ki denga pepo”
which describes a sudden cramping seizure caused by an evil spirit! Let me
assure you that the local brand of Dengue Fever owes nothing to spirits,
evil, bottled or otherwise.
The dengue virus is related to Japanese
encephalitis, Murray Valley encephalitis and Yellow fever, and there are
four “serotypes” or subgroups of it.
The mosquito lays its eggs in water
containers, preferring the clean water found in water tanks and pots, in the
saucers under pot plants and even under the pet’s food dish. Inside
discarded car tyres is another favorite spot. These mosquitoes are not of
the adventurous type and feed during the day and spend their time within 200
meters of their hatchery. Consequently, the eradication of any local
breeding areas becomes very important towards maintaining your own health,
as you can see. Keep your home free from lying water for a radius of 200
meters and you’re looking good!
Simple Dengue (if you can call it that)
has an incubation period of around four to seven days and then the full
blown symptoms of high fever and headache begin. The headache is usually
behind the eyes and is made worse by eye movement. From there the pains
progress to the limbs with acute muscle pains, which gave it the old name
“Break Bone Fever”.
On the other hand, Dengue Hemorrhagic
Fever (DHF) can certainly be fatal! It appears that Serotype 2 may be the
culprit here, but does not usually produce DHF unless you have been
previously bitten by types 1, 3 or 4. In addition to the symptoms of
Classical Dengue the skin begins to bruise very easily as the blood
hemorrhages into the skin. Children are generally more susceptible to this
than adults. This also becomes much more of an emergency and is best treated
in the Intensive Care Unit (ICU) of your favorite hospital.
With our ability to treat the viral
ailments being very limited, the defense against the Dengue virus used to
lie in the preventive measures. The other precautions are to wear long
trousers and long sleeved shirts, especially at sun up and sun down, when
the mosquito is at its most ravenous. The other factor to remember is “D”
for Dengue and “D” for DEET. DEET is the magic ingredient in mosquito
repellents, so when you go to buy some, check the label – if it has DEET,
then get it. However, there is also now a vaccine against Dengue (ages
9-45), available at the Bangkok Hospital Pattaya till February 28. B. 9,600
for three injections. Looks worthwhile to me.
Good Exercise. Does that include sexercise?
The new check-up programs are out in my
hospital with all the discounted items so you can chart your health (or
otherwise) and star remedial action.
Probably the commonest advice a doctor
gives to patients who have just done a check-up is to lose weight and get
some exercise. Does that ring a bell in your memory? Was that part of the
advice after your annual physical check-up?
Unfortunately, there seems to be very
little real understanding of what exercise should consist of, how often,
what type, how long and what about sex? For example, I was reading an
article on exercise the other day and it said authoritatively that one
should wear comfortable clothing and socks with the correct size of
non-slippery, shock-absorbing shoes. If this includes sexercise, there are
some strange shoe fetishes out there that I haven’t heard of yet!
However, getting a little serious,
exercise will be good for you, provided that you pick a form of exercise
that is not harmful for you! Now I know that looks as if I have put my money
on every horse in the race, but take that sentence at its face value.
Enough research has been done to show
that regular exercise is beneficial for everybody, in both the physical and
psychological aspects, but, and it is a big ‘but’, all forms of exercise
have relative bodily risks, and this has to be taken into account before you
buy a pair of expensive jogging shoes and tackle a 10 km trot up Pratamnak
Hill in the middle of the day.
True stories – a medical colleague in
Australia took up playing squash when he turned 50 to improve his fitness
and dropped dead on the court of a heart attack, and another acquaintance of
mine turned 40, decided he wasn’t fit, bought a bicycle to ride to work each
day and was run over by a bus.
The same article that advised
non-slippery shoes, did have some wise words, however. These included to
choose appropriate exercise according to your ability. Never exceed your
limit. Remember that it is not the harder the better. If you have acute
medical problems (such as fever, or pain), stop exercising. If you have
chronic medical conditions (such as hypertension, diabetes, ischemic heart
disease and arthritis), seek advice from your doctor or physiotherapist
All of these I agree with. Remember
that if you are happy to take your body to your medical advisor when it is
sick, take it back to your doctor for advice on how to keep it fit as well.
The other words of wisdom in the
article suggested that for prolonged exercise such as hiking, continually
drink water to supplement the loss of body fluid due to sweating. Do not
wait until you are thirsty. Take appropriate breaks during exercise. Do not
over-exert yourself. Forget about “powering through the pain barrier”. Leave
that for Tour de France cyclists and their “special” hormones.
As well as the form of exercise, there
is the frequency. At least three times per week is recommended and 20-30
minutes (or more) is necessary each time, to derive the maximum benefit. And
always remember, if there is dizziness, fainting, shortness of breath, chest
pain, vomiting, nausea or severe pain during exercise, stop exercising
immediately and seek medical advice as soon as possible.
Now I did mention at the start of this
week’s article, the word “sexercise”, and some of you have been impatiently
reading, while nervously fiddling with your expensive packet of Viagras,
Kanagras, Cialis, Sidegra and other lead-in-your-pencil medications (I draw
the line at tiger willy). OK, what about sex? The advisability of this form
of exercise when you have some chronic complaint (such as hypertension,
diabetes, ischemic heart disease, etc.), should be part of the advice you
get from your doctor beforehand. The danger of over the counter willy
stiffeners is that you don’t get advice with them and the strain of sexual
activity may not be the best for you.
Finally, the learned article did say
“Exercise with friends. Company provides enjoyment, mutual encouragement and
support.” That goes for sexercise too I would imagine, but take the joggers
The Seven Deadly Sins!
Heart disease is still one of the
greatest killers of mankind, ranking a strong second after the Songkran road
toll – OK, I exaggerated that a little, but I still maintain that any
celebration in which 500 people get killed is a blight on the face of our
Interestingly, if you look at the major
causes of death by development of the countries, in the high income
countries death toll comes from heart disease, stroke and lung cancer,
middle income countries have stroke, heart disease and lung disease and for
the low income countries it is heart disease, respiratory infections and
There are many reasons for the
differences, including dietary, socio-economic, educational, development of
health services and tobacco and alcohol abuse. However, this week I am only
going to address heart disease, and the seven deadly ‘sins’ that can predict
your likelihood of getting (and suffering from) heart disease.
1. High Blood Pressure: 20 percent of
elderly people suffer from this condition. Imagine trying to blow through a
long tube. If the tube becomes constricted for any reason, you will have to
blow harder, increasing the pressure. Blood pressure is the same – if the
arteries are constricted or less pliable, it takes a greater pressure to
force the blood around. The heart has to work harder to produce the
increased pressure, and eventually the heart gets tired and fails.
2. High cholesterol: High cholesterol
foods such as egg yolk, offal, animal brain, animal fats, dairy products,
seafood, oyster, squid, etc., leave deposits in the blood vessel walls. As a
result, the fat “plaque” on the vessel walls obstructs the blood flow and
this will eventually cause heart disease, as per the first deadly sin above.
3. Smoking: Smoking is a primary factor
in the causation of coronary artery disease. Smokers are at a much higher
risk, even two times more than non-smokers. Smoking increases adrenaline,
which causes an increased heart rate, increased blood pressure and lowers
the amount of oxygen carried by the blood.
4. Diabetes: Diabetic people have twice
the risk of congestive heart failure than people with normal blood sugar
levels, due to their increased weight (see number 5) and high cholesterol
levels produced in the blood.
5. Obesity: People who are fatter than
average have to face a 30-40 percent increase in risk of heart disease
compared to thin people. In just carting around the extra weight, the heart
has to work harder (and the knee and hip joints wear out). Try walking
around with 10 kg extra on your back and tell me how you feel at the end of
a week. Tired? Of course. And your heart is tired too.
6. Stress: Stress is not totally bad
for us, as it keeps you going, and in an appropriate level actually
stimulates our curiosity and motivation; however, by getting over-stressed,
adrenaline levels are increased and this may lead to abnormal heart
function. Though stress is not the main cause of heart disease, it can make
the artery walls less flexible, which is the beginning of heart disease.
7. Lack of exercise: Exercise is the
best way to increase high density lipoprotein (HDL) – “good” cholesterol
that prevents the arteries becoming abnormal. By exercising, blood pressure,
body weight, and the possibility of thrombosis will be reduced.
So you can see just how these seven
risk factors all are inter-related. Keep the arteries clean, watch the diet
and ensure you have a reasonable level of exercise. Check the Blood Pressure
and stop smoking.
Remember too, that as you get older,
the chances (and risks) of heart disease are higher. (Young males are more
likely to die from Songkran effects than heart failure.) Statistically, men
aged over 40 years as well as the postmenopausal women have a higher risk
Despite our knowledge, we still cannot
predict exactly when the demise will come, but looking at the big picture,
we do know that smoking, overweight, unfit diabetics with high blood
pressure and high cholesterol do not live as long as non-smoking, fit, lean
people with normal blood pressure, and normal blood sugar and cholesterol
Do you know your levels? A brief
medical check-up will tell you.
A PET scan is not
an X-Ray of your dog
There is only December
30 and 31 left in which to pay to get the discounted Check-up Packages in my
hospital. However, as long as you have paid before December 31, you have
till February 28 to actually have the physical examination.
The usual request is “I
want everything.” And by that they mean blood testing. If I told them that
sitting on my desk is the “Manual of Use and Interpretation of Pathology
Tests” which is almost 400 pages and there are about five tests per page.
Imagine the bill for all that lot! But I doubt if many of you need Basement
Membrane Antibodies to be done for any reason.
There is also, in the
collective subconscious, interest in a “whole body scan” which is thought of
as some magical device that you can walk into in one end and out the other
and a print-out will tell you (and us) exactly how you are inside and out.
Every organ! Even Willy the Wonder Wand! Unfortunately, this is stretching
the truth somewhat. Machines like that are only seen in Star Trek movies.
However, there is the
PET scan, which is a specialized form of whole body scanner, that can give
an indication of what is going on inside.
PET stands for Positron
Emission Tomography and is a type of nuclear medicine imaging. Nuclear
medicine is a subspecialty within the field of radiology that uses very
small amounts of radioactive material to diagnose or treat disease and other
abnormalities within the body.
imaging procedures are noninvasive and usually painless medical tests that
help physicians diagnose medical conditions. To be able to produce the
images in a PET scan, you have to have radioactive materials, called a
radiopharmaceutical or radiotracer, and these are injected into your veins.
The radioactive material has a very short life and is usable for only about
two hours, though it will take a day before you have excreted it all.
The radioactive energy
is detected by a device called a gamma camera, a (positron emission
tomography) PET scanner. These radiology devices work together with a
computer to measure the amount of radiotracer absorbed by your body and to
produce special pictures offering details on both the structure and function
of organs and other internal body parts.
The PET scanner is most
usually used in cancer medicine and can demonstrate a ‘hot spot’ to show up
the primary cancer, stage a cancer, show any metastases (spread), and even
show whether cancer treatment modalities are working. For example, the PET
scan can show the difference between scar tissue and active cancer tissue.
The benefits provided
by PET scans are primarily because the information provided by nuclear
medicine examinations is unique and often unattainable using other imaging
For many diseases,
nuclear medicine scans yield the most useful information needed to make a
diagnosis or to determine appropriate treatment, if any.
Nuclear medicine is
much less traumatic than exploratory surgery.
By identifying changes
in the body at the cellular level, PET imaging may detect the early onset of
disease before it is evident on other imaging tests such as CT or MRI.
The risks are very low.
Because the doses of radiotracer administered are small, diagnostic nuclear
medicine procedures result in minimal radiation exposure. Thus, the
radiation risk is very low compared with the potential benefits.
Nuclear medicine has
been used for more than five decades, and there are no known long-term
adverse effects from such low-dose exposure.
Allergic reactions to
radiopharmaceuticals may occur but are extremely rare.
Injection of the
radiotracer may cause slight pain and redness which should rapidly resolve.
Women should always
inform their physician or radiology technologist if there is any possibility
that they are pregnant or if they are breastfeeding their baby.
Can you get this kind
of scan here? Yes, at Wattanosoth Hospital in Bangkok, and it costs around
60,000 baht last time I asked. However, if you purchase a Chivawattana
personal health insurance card (available at Bangkok Hospital Pattaya) it
has a discount for the PET scan (as well as many other benefits). Well
worthwhile looking into if a PET is on the agenda.
Christmas Disease – it’s not Happy Holiday disease!
has nothing to do with Happy Holidays, Christianity, or Santa, mangers,
three wise men and a bottle of myrrh. But it has everything to do with
Stephen. And not St. Stephen but Stephen Christmas, that is.
Stephen, a young
British lad, was the first patient with a bleeding tendency recognized
to have a different form from “classical” hemophilia (or haemophilia if
you come from the right hand side of the Atlantic Ocean).
His condition was
studied by researchers Biggs, Douglas, and Macfarlane in 1952, who
discovered that young Stephen was missing a different coagulation factor
than the more usual one (which is known as Factor VIII). They named
Stephen’s missing factor as Factor IX, and his condition became known as
Just to confuse the
issue, we also call Christmas Disease by other names, including Factor
IX deficiency, hemophilia II, hemophilia B, hemophiloid state C,
hereditary plasma thromboplastin component deficiency, plasma
thromboplastin component deficiency, and plasma thromboplastin factor-B
deficiency. There’s probably more, but Christmas Disease has a much
nicer “ring” to it. (Probably “Jingle Bells” at this time of year!)
From the diagnostic
viewpoint, it is very difficult to differentiate between classical
hemophilia (my editor comes from the left hand side of the Atlantic, so
it is spelled with “e”) and Christmas Disease. The symptoms are the
same, with excessive bleeding seen by recurrent nosebleeds, bruising,
spontaneous bleeding, bleeding into joints and associated pain and
swelling, gastrointestinal tract and urinary tract hemorrhage producing
blood in the urine or stool, prolonged bleeding from cuts, tooth
extraction, and surgery and excessive bleeding following circumcision.
covers around one in seven cases of the total hemophilia incidence and
is around 1/30,000 in the general population. This disease is also male
dominated, being called a sex-linked recessive trait passed on by female
carriers. This means the bleeding disorder is carried on the X
chromosome. Males being of XY make-up will have the disease if the X
they inherit has the gene. Females, who have XX chromosomes, are only
carriers if either X has the bleeding gene.
Hemophilia has been
noted in history for many years, and Jewish texts of the second century
A.D. refer to boys who bled to death after circumcision, and the Arab
physician Albucasis (1013-1106) also described males in one family dying
after minor injuries.
In more recent
history, royal watchers know that Queen Victoria of Britain’s son
Leopold had hemophilia, and that two of her daughters, Alice and
Beatrice, were carriers of the gene. Through them, hemophilia was passed
to the royal families in Spain and Russia, leading to one of the most
famous young men with the disease, Tsar Nicholas II’s only son Alexei.
In the 1800’s
physicians thought that the bleeding occurred because of a structural
problem in blood vessels. In 1937 a substance was found in normal blood
that would make hemophilic blood clot, which was named “anti-hemophilic
In 1944 researchers
found in one case that when the blood from two different hemophiliacs
was mixed, both were able to clot. Nobody could explain this until 1952,
when the researchers in England realized there were two types of
hemophilia. They called his version hemophilia B, or “Christmas
disease,” and the more prevalent kind hemophilia A, or “classic
With the discovery
of A and B types came the realization that there must be different types
of “anti-hemophilic globulin” involved in the clotting process. Names
were assigned to these various “coagulation factors” by an international
committee in 1962. Hemophilia A is a deficiency of Factor VIII, and
hemophilia B is a deficiency of Factor IX.
Once it became
clear that hemophilia was caused by a deficiency of a coagulation
factor, replacement of the missing factor became the method of
treatment. In the early 1950’s animal plasma was used. By the 1970’s,
coagulation factor concentrates made from human plasma were available,
and by the 1980’s we could guarantee that it was HIV free. It has been a
long road since Stephen Christmas.
check-up packages at Bangkok Hospital Pattaya have to be paid for by
December 31, but you can delay having the test up till 28 February 2017.
Where’s my readers?
I don’t need
these any more!
By “readers” I don’t mean those kind
souls who read my columns, but I am referring to reading glasses. I just
opened my top drawer at work and there were eight pairs of readers! No, it
wasn’t a “Buy 1 and get 7 free!” These were the result of wear and tear,
broken side pieces, lenses missing, broken frames, unsuccessful repairs with
Super Glue or Araldite (the Greek Goddess of stickiness) and the list goes
on. I did, however, manage to successfully glue my finger to one lens with
Super Glue. It did neither the lens, or my finger, any good at all.
A little history here, which will
probably remind you of your time of decreasing visual acuity.
26 years ago I was ready to admit that
my near vision was gone. Reading a map was just not possible, even holding
the map in front of the headlights. A visit to the optometrist saw me
leaving with suitable contact lenses which introduced a whole new world to
my life. I could read the destination signs on busses and street signs
Unfortunately this Utopia was not to
last. Stronger prescriptions for the contact lenses did help, but were not
the answer. Remembering to remove the contacts every night was a bit hit and
miss, but I always knew in the morning as the lenses were stuck to my
eyeballs and everything was blurred.
I did try and remember to use a sterile
technique putting the lenses in, but that too would fail regularly and I
would have to do without, which suggested to me that a white stick and a
Labrador was next. Of course there were also the dropped lenses with me on
all fours looking for the errant bit of soft plastic.
I struggled on, but then found that my
distance vision was not as good as it used to be. Recognizing faces across
the street was difficult. By now I had arrived at a situation where driving
at night was taking my life in my hands.
It was at this point that I discussed
my vision with Dr. Somchai Trakool Choke-satian in the SuperSight surgery
department at the Bangkok Hospital Pattaya.
It was at that initial consultation
that I discovered that SuperSight was not just changing the lens in the eye,
but a thorough eye examination to ensure that the eye itself is healthy,
other than the cataracts and hardening of the natural lens. This examination
takes about one hour, so it’s not a case of “Read the bottom line,” and it’s
all over style exam.
Dr Somchai advised me that my eyes were
suitable for the SuperSight lenses and then went on to discuss all the pros
and cons of the surgery and the final results that could be expected, and
then told me to go and think about it.
I did that by speaking to all the
people I knew who had SuperSight surgery done before. To a man the answers
were the same, “Wish I’d done it years ago”.
So a convenient date was selected for
Dr. Somchai and myself and the stage was set. No turning back.
I am asked by others whether the
operation was painful and I can honestly say it was not. It is a weird
sensation having someone ‘inside’ your eyeball, but not painful. Under local
anesthetic I found I could relax and keep my eye still as Dr. Somchai did
his magic. And the results are magical. And the freedom from the glasses is
Now two months after the operation, I
still pat my pocket for the readers as I sit down in front of the computer
and then realize I don’t need them. And as a funny ending, I can now wear
T-shirts without a pocket for the glasses. My wardrobe has doubled! And I
can finally read the numbers on the remote for the TV.
For more information contact the
SuperSight surgery department at the hospital, they are nice people.
Do you have “sugar”
Diabetes is a serious ailment,
which can arise for many reasons, and can affect many systems in the
human body. Diabetes, often called “sugar” by patients, is diagnosed and
monitored mainly through a simple blood test – the Blood Glucose level.
Glucose is a type of sugar found in
fruits and many other foods (this includes lactose and fructose). It is
the main source of energy used by the body. Most of the carbohydrates
that people eat are also turned into glucose, which can be used for
energy or stored in the liver and kidneys as glycogen.
To stop the sugar levels just
increasing daily, a balance is achieved through a hormone called Insulin
which helps the body use and control the amount of glucose in the blood.
Insulin is produced in areas of the pancreas called ‘islets’ and
released into the blood when the level of glucose in the blood rises. In
simple terms, people who do not produce enough insulin develop diabetes.
People can also develop diabetes if they do not respond normally to the
insulin their bodies produce. This occurs most commonly when a person is
overweight, and since obesity is on the rise, so are various types of
Normally, blood glucose levels
increase slightly after a person eats a meal. This increase causes the
pancreas to release insulin so that blood glucose levels do not get too
high. Blood glucose levels that remain high over time can cause damage
to the eyes, kidneys, nerves, and blood vessels, which explains why good
glucose control is important.
There are many ways to carry out
blood glucose tests, including fasting blood sugar (FBS). This is a
measurement of blood glucose after fasting for 12 to 14 hours. For an
accurate fasting blood sugar test, do not eat or drink for 12 to 14
hours before the blood sample is taken. However, water can be freely
taken, as otherwise hemoconcentration occurs to give a falsely high
reading. This is often the first test done to detect diabetes, and
explains why fasting blood tests are usually done when having a medical
The other common test is called the
random blood sugar (RBS). A random blood sugar measurement may also be
called a casual blood glucose test. This is a measurement of blood
glucose that is taken regardless of when the person last ate a meal.
Sometimes several random measurements are taken throughout a day. Random
testing is useful because glucose levels in healthy people do not vary
widely throughout the day, so wild swings may indicate a metabolic
Glucose tolerance testing can also
be done, usually to confirm a condition known as gestational diabetes,
which can occur during pregnancy. An oral glucose tolerance test is
simply a series of blood glucose measurements taken after a person
drinks a liquid containing a specific amount of glucose; however, this
test is not used to diagnose diabetes.
To monitor the treatment of
diabetes, there are another couple of tests which can be carried out.
The commonest is Glycated Hemoglobin, otherwise referred to as HbA1c.
This test actually is an indicator of the average glucose concentration
over the life of the red blood cells (which is taken as over the
previous three months).
Another is the Serum C-Peptide
which is used to investigate low blood sugar levels, done by measuring
the C-Peptide which is produced by the Beta cells in the pancreas.
“Normal” levels may vary from lab
to lab, but generally the range taken for FBS is that the level should
be less than 110 milligrams per deciliter (mg/dL).
Diagnosis of diabetes needs a
fasting blood glucose level higher than 125 mg/dL on two separate days.
A fasting glucose level below 40
mg/dL in women or below 50 mg/dL in men that is accompanied by symptoms
of hypoglycemia (low blood sugar) may indicate an insulinoma, a tumor
that produces abnormally high amounts of insulin. Lower than expected
glucose levels can also indicate Addison’s disease, an underactive
thyroid gland or pituitary gland, liver disease (such as cirrhosis),
malnutrition, or a problem that prevents the intestines from absorbing
the nutrients in food.
So you can see “sugar” is important
which is why we have specialist endocrinologists at my hospital.
where are you now?
Bernardino Ramazzini (1633 – 1714) was an Italian physician
who is considered to be the founding father a rather different medical
specialty called Occupational Medicine. One of the lesser known medical
specialties, this is the study of worker health, how the workplace affects
health, the man-machine interface, industrial exposure to contaminants and
many other occupational hazards. (This is not something very well known in
There are many medical
conditions caused by work, right the way from Housemaid’s Knee and another
example of occupationally induced conditions is ‘Vibration White Fingers’
and comes under the general umbrella of an interesting set of conditions
known as Raynaud’s phenomenon.
Since doctors like to
have conditions named after them, Raynaud’s phenomenon comes from Dr.
Maurice Raynaud, a French physician who published a report in 1862 of a
young woman whose fingertips changed colors when she was cold or under
stress. He is credited with the discovery of the condition.
sometimes called Raynaud’s syndrome or disease, is a disorder of blood
circulation in the fingers. This condition is usually produced by exposure
to cold which reduces blood circulation causing the fingers to become pale,
waxy-white or purple. This condition is sometimes called “white finger,”
“wax finger” or “dead finger”. These attacks occur when the hands or the
whole body get cold either at work or at home. Household or leisure
activities resulting in cold exposure can include washing a car, holding a
cold steering wheel, or the cold handlebars of a bicycle. Attacks of white
finger can also occur when a person is outdoors watching sports, or while
gardening, fishing or golfing in cold weather.
Typical attacks occur
with tingling and slight loss of feeling or numbness in the fingers,
blanching or whitening of the fingers, usually without affecting the thumb,
and pain, sometimes with redness, which accompanies the return of blood
circulation generally after 30 minutes to two hours.
Many cases of Raynaud’s
phenomenon are such that we cannot identify the cause. To escape the
embarrassment of admitting that we just don’t know, we call this “primary
Raynaud’s phenomenon” or even “constitutional” white finger. However, when
we do know the occupational cause of Raynaud’s phenomenon we call it
“secondary Raynaud’s phenomenon”!
In the occupational
sphere, there are many causes of this secondary condition. It is most
commonly associated with hand-arm vibration syndrome but it is also involved
in other occupational diseases. Awareness of the condition can help prevent
the disorder from occurring or progressing, as if not detected in the early
stages, the disorder can permanently impair blood circulation in the
phenomenon is not life threatening, severe cases cause disability and may
force workers to leave their jobs and workman’s compensation issues may end
up in courts of law. Although rare, severe cases can lead to breakdown of
the skin and gangrene. Less severely affected workers sometimes have to
change their social activities and work habits to avoid attacks of white
The underlying cause
relates to the physiology of maintaining an even body temperature. Usually,
the body conserves heat by reducing blood circulation to the extremities,
particularly the hands and feet. This response uses a complex system of
nerves and muscles to control blood flow through the smallest blood vessels
in the skin. In people with Raynaud’s phenomenon, this control system
becomes too sensitive to cold and greatly reduces blood flow in the fingers.
Exposure to vibration
from power tools is by far the greatest concern in secondary Raynauds.
Hand-held power tools such as chain saws, jackhammers and pneumatic rock
drillers and chippers can cause “hand-arm vibration syndrome”. This disorder
is the “vibration white finger”, “hand-arm vibration syndrome (HAVS)”, or
“secondary Raynaud’s phenomenon of occupational origin.” How many times have
you seen Thai construction workers with the flip-flop “safety” footwear
blasting away on concrete floors? Many times I am sure.
induced Raynaud’s phenomenon occurred in the early years, before the
cancer-causing effects of vinyl chloride monomer were known. Workers exposed
to high levels of this chemical also experienced Raynaud’s phenomenon.
So that is the story of
Raynaud’s phenomenon. Fortunately, in our warm tropical climate it is not
seen too often, other than the occupational secondary variety.