It was way back in the 1700’s that a Dr Bernardino Ramazzini (1633 - 1714), an
Italian physician published a book on occupational diseases, “De Morbis
Artificum Diatriba (Diseases of Workers)”. That makes him, in my eyes, the
father of modern Occupational Medicine.
However, Occupational Medicine is still 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. One example of occupationally induced
conditions is known as ‘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.
Raynaud’s phenomenon, 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 fingers.
Although Raynaud’s 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 finger.
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.” However, Ramazzini did state in his book that repetitive violent
movements can produce this condition many years before.
In 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 rarely seen, other
than the occupational secondary variety.
