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.