A transatlantic team of scientists have discovered a secondary sensory system, independent of the well-understood nervous system, hidden in the skin. These may be at the root of inexplicable chronic pain syndromes like fibromyalgia.
"It's almost like hearing the subtle sound of a single instrument in the midst of a symphony," said senior author Frank Rice, PhD, a Neuroscience Professor at Albany Medical College (AMC), who is a leading authority on the nerve supply to the skin. "It is only when we shift focus away from the nerve endings associated with normal skin sensation that we can appreciate the sensation hidden in the background."
The research team discovered this hidden sensory system by studying two unique patients who were diagnosed with a previously unknown abnormality by lead author David Bowsher, M.D., Honorary Senior Research Fellow at the University of Liverpool's Pain Research Institute. These patients had an extremely rare condition called congenital insensitivity to pain, meaning that they were born with very little ability to feel pain. Other rare individuals with this condition have excessively dry skin, often mutilate themselves accidentally and usually have severe mental handicaps...
The answer appeared to be in the presence of sensory nerve endings on the small blood vessels and sweat glands embedded in the skin. "For many years, my colleagues and I have detected different types of nerve endings on tiny blood vessels and sweat glands, which we assumed were simply regulating blood flow and sweating. We didn't think they could contribute to conscious sensation. However, while all the other sensory endings were missing in this unusual skin, the blood vessels and sweat glands still had the normal types of nerve endings. Apparently, these unique individuals are able to 'feel things' through these remaining nerve endings," said Dr. Rice. "What we learned from these unusual individuals is that there's another level of sensory feedback that can give us conscious tactile information. Problems with these nerve endings may contribute to mysterious pain conditions such as migraine headaches and fibromyalgia, the sources of which are still unknown, making them very difficult to treat."
(Image: Nothing But Skin, a Creative Commons Attribution photo from kevindooley's photostream)