Low Level Therapy for treating Herpes Zoster & Chronic Post-Herpetic Neuralgia
Herpes zoster, more commonly known as shingles, can be treated effectively using low-intensity laser therapy. The treatment is also effective for chronic post-herpetic neuralgia. Entirely safe and non-invasive, it is effective for over 80% of patients with these painful conditions.
Herpes Zoster
Herpes zoster is caused by the varicella-zoster virus which is the same virus as that which causes chickenpox. Following a chickenpox infection, the virus can remain dormant in the body’s nervous system without causing any symptoms. It can, however, be reactivated in later life resulting in an unpleasant and painful infection of nerves and surrounding tissue.
The main symptoms are a painful and itchy rash that develops into blisters resembling those of chickenpox. The pain can vary from mild-to-severe, and while in many patients it disappears after the rash has gone, generally within two or three weeks, with some patients, pain can persist for considerably longer. The rash tends to form patterns as it follows the nerves, and it is rare for it to affect both sides of the body. Additional symptoms may include a headache, fever, and general malaise.
For most people, the condition isn’t serious, though it has the potential to affect the trigeminal nerve which can result in visual impairment. Although rare, other cranial nerves can also be affected which can result in cognitive problems, facial paralysis, encephalitis, and meningitis.
When the pain continues after the rash has gone, the condition is known as post-herpetic neuralgia. This happens with around 20% of patients, with older patients being more vulnerable, and results from long-term damage to the affected nerves. The condition is difficult to manage and for some people it can be debilitating, affecting their daily lives.
Traditional treatment
There is no known cure for shingles, through various traditional treatments are available for treating the symptoms. Analgesics such as ibuprofen and paracetamol can reduce the pain and antiviral medicines such as acyclovir, famciclovir, and valaciclovir can be used to reduce the severity of the infection, though to be effective antiviral treatment should commence within 72 hours of initial symptoms.
For more severe cases of pain, prescription NSAIDs or narcotic painkillers may be necessary. In some cases, corticosteroids can be prescribed to ease the discomfort, inflammation, pain, redness, and itching associated with shingles’ rash and blisters.
When the pain from post-herpetic neuralgia is particularly severe, codeine and other opiate drugs can bring relief, though there are potentially serious side effects. Antidepressant drugs have also proven effective. Vaccination against shingles is also available.
Low-level laser treatment
As has been extensively reported in numerous studies, low-level laser treatment provides a safe and effective treatment scheme for both herpes zoster and chronic post-herpetic neuralgia. For instance, Iijima K et.al. (1991) reported successful results on a group of 18 post-herpetic neuralgia patients using irradiation with low-power He-Ne laser and (Iijima K et.al. 1989) up to 88.9% effectiveness on another group with around 55% pain relief.
In a double-blind cross-over trial (Moore K, et.al. 1988) on post-herpetic neuralgia patients of at least 6 months duration who had shown no response to conventional treatment laser treatment provided a significant reduction in pain intensity and distribution in 74% of patients.
How low-level laser treatment relieves shingles and chronic post-herpetic neuralgia
Low-level laser therapy uses infra-red LED lasers, and the laser light produced does not heat the skin. Instead, there is a photochemical interaction between the tissue and the laser beam that occurs at a cellular level.
Although there is no clear consensus on the actual mechanism, our understanding of it is increasing constantly. Recently Kalid M.Z. (2016) studied the mechanism of laser beam interaction at both cellular and tissue levels using different light sources and dosimetry and Chung, Hoon, et al. (2012) examined the nuts and bolts of the therapy in a similar study.
Essentially, the cold laser is thought to change cell membrane permeability. Photons are absorbed in the mitochondria of the cell accelerating cellular reproduction and growth. Fibroblast development is stimulated and metabolic rate is increased. Swelling is reduced, blood flow is increased and the laser stimulates nerve cell healing and communication.
Finally
Today we are seeing excellent results from laser therapy in the treatment of acute herpes zoster and chronic post-herpetic neuralgia. The treatment is entirely safe, non-invasive and usually brings rapid relief. Some patients report immediate improvement during the first treatment.