Biological cause of chronic pain after shingles discovered

The varicella zoster virus, which remains dormant in the body of people who have recovered from chickenpox in the past, is reactivated as rash shingles in later ages. In approximately 18 percent of patients, an unbearable and chronic pain condition called "postherpetic neuralgia" develops, even if the rash disappears.

"EXOSOMES" CIRCULATING IN THE BLOOD LOCK THE SELF-REPAIR OF THE NERVES

Neurovirologists studied particles of "exosomes," cellular carriers in the blood of patients suffering from chronic pain. Laboratory analyzes revealed that the exosomes in the blood of these patients were filled with special proteins that suppress nerve growth.

Experiments conducted on live human neurons documented that nerve cells exposed to exosomes from people with postherpetic neuralgia were stunted, unable to form the "growth cones" needed to repair themselves, and unable to establish a communication network with other neurons.

NEURONS ARE CONSTANTLY KEPT IN AN OVER-EXCITED STATE

Research data showed that these microscopic cellular cargos keep pain sensory neurons in a constant state of hyperexcitability. Nerve fibers cannot heal after the rash, and they become hypersensitive to pain signals due to the biological pressure created by exosomes.

This provides a logical basis for why patients feel severe pain for years, as if their tissues were damaged, even if the virus is cleared from the body.

NEW HOPE FOR DIABETIC NEUROPATHY AND OTHER CHRONIC PAIN

Researchers report that these findings will not be limited to post-shingles pain, but can also be used in the treatment of other chronic pain disorders such as "diabetic neuropathy", in which nerve repair stops.

By targeting exosome cargo in the blood, the development of new generation biological treatments has begun that will directly repair nerve cells and stop overstimulation, instead of the symptoms that were tried to be relieved with painkillers but were unsuccessful.