IRSST issues alert on hypothenar hammer syndrome

Hypothenar hammer syndrome is an insidious disease that can be easily confused with other disorders, such as hand-arm vibration syndrome or Raynaud’s disease, which are also characterized by blanched fingers. To alert employers and workers, the Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST) has published an information pamphlet entitled Recognizing Hypothenar Hammer Syndrome.

HHS is a rare and little-known disease that can lead to serious injury in the affected fingers and could even result in their amputation, if the diagnosis and the treatment are not appropriate. The disease develops in workers who use vibrating tools or who repeatedly use the palms of their hands to strike, flatten, press or twist objects. Even a single episode of trauma could cause the disease. These ways of working can cause a reduction in blood flow circulating into the fingers, especially the middle, ring and little fingers.

“Workers should be vigilant and they should not wait before consulting a physician to avoid severe complications,” said Alice Turcot of the Institut national de santé publique du Québec. “Certain symptoms such as white or blue fingers that are stiff and painful are easily observable. Often, the affected hand will be hypersensitive to cold, it will lose strength, and there will be a sensation of pins and needles or numbness in the fingers. To prevent the syndrome, workers should, first and foremost, not use their hand as a hammer, and they should not grip tools such as impact wrenches, pliers, scissors and even vehicle gearshifts too tightly.”

The workers most vulnerable to hypothenar hammer syndrome are machinists, construction workers, miners, mechanics, forestry workers and farmers. A number of tools can cause the disease, including electrical or pneumatic vibrating tools, brush cutters/trimmers, milling machines, grinding machines, jackhammers, impact wrenches, pliers and presses.