This post will be reviewing a research study entitled "Role of low-level laser therapy in post-herpetic neuralgia: a pilot study," which was published in Lasers in Medical Science in January of 2020. Specifically, we will be talking about shingles pain with laser, and it's exciting stuff!
Post-herpetic Neuralgia
Shingles is technically called post-herpetic neuralgia (which translates to nerve pain after the shingles virus), and this post-herpetic neuralgia is the pain that persists after those shingles’ blisters have resolved. Although not every case of shingles will have residual pain afterwards, a lot of them do, and most of those patients' residual pain persists for a long time. In this study we're reviewing, the authors note that "post-herpetic neuralgia is a painful condition which affects nerve fibers. It's the complication of herpes zoster [the shingles virus] and it affects 50% of individuals over the age of 50 who have had shingles." That's a large percentage of people!
In many cases, the pain can last for months, or even years. Some individuals experience up to 20 years of sever, constant pain. The researchers say that "the pain complaints are often linked to feelings of tickling, burning, stabbing pain, a feeling of shooting or cutting pain, the feeling of crawling insects or trickling, sweat drops." We have also heard patients describe this discomfort as a sensation of a hair continuously brushing against the skin. In many cases, though, the pain that occurs after shingles manifests as stabbing and burning sensations.
What is Shingles?
Before going into what the findings of this study were, let's discuss the shingles virus itself. It's a virus that tends to hide inside the nerve. It can then become activated through either trauma or stress (there's a lot of different factors that can activate the virus). Once this happens it irritates and inflames the nerve, resulting in pain and blister eruptions along the path of the nerve. This is very common along the rib cage, so these cases will cause pain that runs in a horizontal line along the ribs. It follows the ribs' pattern because that is the pathway the nerve takes from the spine out and around the outside of the body for cutaneous skin sensation. Also, because it's a nerve that carries sensation from the skin, when it gets inflamed, it becomes hypersensitive and sends more pain signals than it should. That dysfunction of the nerve is what also causes those blister eruptions. If you can get the virus under control and settle that nerve, the eruptions and the pain will dissipate—in about half of the cases. In the other cases, the nerve is so inflamed and sensitive that it will sustain that painful sensation, even when the virus is dormant. If the nerve is still on high alert, it's still sending pain signals.
This study was researching that second type of cases where the pain is sustained even after the actual shingles outbreak is contained. It is explained in the study that the pain does "result from the inflammation of the sensory dorsal root ganglia of the affected skin," which is a part of the nerve back towards the spine. They say that "chronic neuropathic pain needs medications on a regular basis, and those medications typically involve things like anticonvulsants, antidepressants, opioid medication, [Tegretol, Gabapentin, Lyrica, medications like those], can be prescribed. However, they do come with some significant side effects and some level of risk as well." That is why they did this study on shingles pain with laser treatments.
Shingles Pain Study
The researchers enrolled patients who had been suffering from this post-herpetic neuralgia for a month to a year and who had experienced no good response to the pharmacological treatments like Tegretol and Gabapentin. They were not receiving pain relief from those drugs, even after their outbreak of shingles had already been contained. For these patients whose active shingles outbreak was gone but whose post-shingles pain persisted, the researchers used laser therapy. The goal was to reduce these patients' nerve pain. Let's see how it worked.
Quoting the study: "[L]aser therapy has shown significant effects in reducing pain associated with neuralgia or nerve pain. When tissue is stimulated with laser therapy, its regeneration is initiated, which includes new vessel formation, muscle and nerve regeneration, and production of cartilage collagen and even bone. It has a significant effect in reducing inflammation that causes the abnormal stimulation of nerves." In the case of post-herpetic neuralgia, they say "the safety and efficiency of laser therapy has been evidenced in treating a variety of skin diseases and in physiotherapy or physical therapy, it's used to treat a wide variety of chronic musculoskeletal aches and pains. In dentistry, it can be used to treat inflamed oral tissues and ulcerations and in dermatology to treat edema, ulcers, burns, dermatitis, and acne and for rheumatology to relieve pain and treat chronic inflammation and wound healing." So, as you you can see, laser can help a lot of things! Because the researchers had some evidence that laser can be used for nerve pain reduction, they began doing laser treatment on these patients. They applied 2 laser treatments per week for 8 weeks, for a total of 16 sessions. They applied non-invasive red laser to the painful spots along the rib cage, delivering 1 minute of light per spot.
Laser Therapy for Chronic Shingles Pain
By the end of the treatments, many of these patients went from severe pain to no pain at all. And, remember, these are patients who had been experiencing consistent pain for up to a year after their shingles outbreak had been "resolved." This pain relief was not going to happen on its own, so they had tried medications with very poor results; but laser therapy actually stimulated a massive reduction in their pain. The researchers reported, "Laser provides a non-invasive, painless, and safe method of therapy. Amazingly, patients get treated without any medication. In addition, this helped patients avoid the side effects of medicines. It can be concluded that laser therapy is an efficient modality for pain management in post herpetic neuralgia."
That said, just because they saw these results does not mean that every single person with shingles pain will always get total relief. They observed a number of patients in their study who did feel significant relief, but not full resolution. They had patients that went from an 8/10 level of pain, down to a 3/10; that is still a great improvement, and perhaps ongoing laser treatments could provide further relief.
Now, let's quickly address a quick question: Does the pain relief last, or does the pain come back? Fortunately, the researchers tracked this and reported that the pain relief lasted for at least several months, as that is how long they continued monitoring the research participants.
In summary, if you are struggling with pain after having had shingles, laser treatment might be a good option for you, and one you might want to try before turning to medications. To get started, find a laser therapy clinic near you!
