Post herpetic neuralgia is a complication of shingles. It is believed to be the result of permanent damage to the nerve from the varicella-zoster virus.
What is Post Herpetic Neuralgia?
Post -herpetic neuralgia (PZN) occurs in 10 to 15 percent of all patients with shingles (herpes zoster). Those affected suffer from neuropathic pain in the area of the previous zoster infection. With herpes zoster on the face, the PZN occurs much more frequently than with other zoster localizations. See howsmb for CBAVD Definition and Meaning.
The likelihood of developing post-herpetic neuralgia after shingles also increases with age. The pain is sometimes very severe. Even painkillers help little or not at all. Post-herpetic neuralgia cannot be cured and the pain persists. Due to the persistent severe pain, patients with PZN are often suicidal.
Causes
Post-herpetic neuralgia is caused by infection with the varicella-zoster virus. Such an infection is colloquially called shingles. The varicella-zoster virus belongs to the herpesvirus family . It is closely related to the herpes simplex virus. It is estimated that the virus infection rate is high. Around 90 percent of all Europeans over the age of 14 are carriers of varicella-zoster viruses.
The pathogens rarely cause diseases with a fatal outcome. This shows how well the viruses have adapted to their reservoir host, humans. The initial infection with the virus is usually manifested by chickenpox. The pathogens are transmitted by droplet infection. Smear infections are also possible. After the chickenpox disease has subsided, the sufferers are immune to chickenpox for life.
However, the varicella-zoster virus remains in the body. The virus can later be reactivated at any time due to a suppressed immune system . Frequent triggering factors are stress or strong sunlight. The viruses persist in the nerve roots of the spinal cord, in the so-called spinal ganglia, and in the ganglia of the cranial nerves.
When the virus is reactivated, chickenpox does not occur again, but rather shingles. Post-herpetic neuralgia is caused by impaired transmission of stimuli caused by viruses on the nerves. The viruses can leave permanent damage to the affected nerves. These cause the chronic pain.
Symptoms, Ailments & Signs
Post-herpetic neuralgia is always the result of shingles. The viral disease presents as a painful blistering rash on one side of the body. The rash runs in stripes on a specific dermatome. A dermatome is an area of skin innervated by a spinal nerve.
In most cases, shingles is preceded by a so-called prodromal stage. Symptoms such as exhaustion, fever and tiredness appear in this early stage. Burning, pain and discomfort can also occur in the affected dermatome. Only a few days later does the typical rash appear. Nerve tissue is inflamed, and sufferers experience burning and severe pain in the dermatome supplied by the inflamed nerve.
The nerve cord itself can also hurt. Within a few days, the resulting blisters fill up and break open. Healing can take two to four weeks. The pain usually subsides within a few weeks. However, permanent nerve damage can cause neurological pain for a very long time.
These are known as post-herpetic neuralgia. The pain can appear in different forms. It can be permanently burning and nagging or appear in the form of brief and severe attacks of pain. Severe touch pain is also typical of post-herpetic neuralgia.
Diagnosis & course of disease
Diagnosis is based on presenting symptoms, medical history, and physical examination. If post-herpetic neuralgia occurs in younger patients, the reasons for the immune deficiency should always be sought. In young patients, post-herpetic neuralgia occurs only in very rare cases without an immunosuppressive cause.
Immune system disorders can be acquired or congenital. Malignant diseases such as tumors and leukemia must be clarified in any case. Systemic diseases and infectious diseases such as AIDS should also be ruled out.
Complications
Depending on the intensity and duration of the post-herpetic pain, depressive moods, the development of clinically manifest depression, easy fatigue and exhaustion can occur. Difficulty falling asleep and staying asleep, reduced appetite and difficulty concentrating. People who have had neuropathic pain for more than a year are at greatest risk of these complications.
A high pain intensity also increases the probability of long-term effects. Since the therapy of post-herpetic neuralgia is symptomatic according to the quality of the pain, complications can also arise from inadequate or incorrectly performed pain therapy.
This applies in particular to antidepressants containing the active ingredients nortriptyline, duloxetine and venlafaxine, which are used both to treat depression and to treat pain. Dosages that are usually chosen for the treatment of neuralgia are often not sufficient for the treatment of depression and may have to be adjusted.
Anticonvulsants with the active ingredients gabapentin and pregabalin, which are also used to reduce post-herpetic pain, can increase existing complications such as tiredness and poor concentration.
This applies to an even greater extent to painkillers from the opioid drug class (tramadol, oxycodone, morphine). Their partially desirable sedative effect, in interaction with existing complications and other painkillers, can lead to severe tiredness, drowsiness and confusion. In order to avoid complications, the pain therapy should therefore be adjusted regularly.
When should you go to the doctor?
If severe nerve pain occurs suddenly, a doctor’s visit is recommended. Post-herpetic neuralgia is treatable if caught early. Therefore, nerve problems, problems moving the limbs and other unusual symptoms should be examined and, if necessary, treated by a doctor. Anyone who has recently contracted the varicella-zoster virus should consult their family doctor. It is possible that the neuralgia was triggered by the pathogen. People with a weakened immune system, nervous disorders and severe shingles should also consult a doctor if the symptoms described occur.
Medical advice is required at the latest when the symptoms have a very negative effect on well-being or lead to further physical or mental problems. In addition to the general practitioner, post-herpetic neuralgia can be seen by a neurologist or internist. Chronic diseases may require inpatient treatment in a specialist clinic. Those affected should discuss with the doctor which measures promise the best prospects of recovery with regard to the symptoms and any previous illnesses.
Treatment & Therapy
Post-herpetic neuralgia can only be cured in very rare cases. If the disorder started less than six weeks ago, a sympathetic blockade can be done. In intravenous regional sympathetic blockade, a drug is injected into a vein next to the affected area of skin. The administered sympatholytic can relieve the pain.
If the disease persists for more than six weeks, this method is not promising. Affected patients receive painkillers such as tramadol or pregabalin. Antidepressants or gabapentin are also administered in low doses. They can inhibit the transmission of pain in the brain and at the same time alleviate depressive moods. Many patients with post herpetic neuralgia suffer from depression due to the intense pain.
Psychotherapy can also be carried out to make it easier for patients to deal with their illness. In some cases, local anesthetic ointments or patches are used. Some doctors also treat post herpetic neuralgia with capsaicin cream. Capsaicin, an active ingredient in chilli pepper, binds to the pain receptors in the skin and disrupts the transmission of stimuli.
Accompanying the pain medication, transcutaneous electrical nerve stimulation (TENS) can be carried out. The patient wears a small device that is connected to the affected area of skin via an electrode. When pain occurs, the patient can deliver electrical impulses. These irritate the skin nerves and impede the transmission of pain impulses.
Prevention
To prevent post-herpetic neuralgia, any shingles should be treated early with antiviral drugs such as valaciclovir and aciclovir.
Aftercare
After the actual herpes infection has subsided, some patients may experience discomfort or pain in the affected area. The treatment of these symptoms requires the active cooperation of the patient, since the symptoms can otherwise become chronic. First of all, it is important to take the medication prescribed by the doctor correctly.
In addition, pain-relieving gels will help. Acupuncture and TENS therapy have also shown success in the treatment. TENS therapy is a gentle variant of electrotherapy. A stimulation device generates a current that blocks the conduction of the nerve fibers so that they cannot transmit the pain impulse to the brain. TENS devices are also available for home use, which makes them much easier to use.
Appropriate relaxation techniques, such as Jacobson’s progressive muscle relaxation, can also help against the discomfort and pain. Yoga, Reiki or certain breathing exercises also enable the patient to relieve the symptoms of post-herpetic neuralgia and to deal with them more calmly. In particularly severe cases or if the pain has already become chronic, psychotherapeutic therapy can be used in addition to drug treatment, which is intended to help the patient to lead a largely independent and carefree life.
You can do that yourself
This discomfort or pain that occurs after a herpes infection is particularly annoying for the patient because the actual infection has already subsided. Nevertheless, you should actively participate in the treatment, otherwise the symptoms could become chronic.
Treatment includes taking the medications prescribed by the doctor correctly. Pain-relieving gels can also be used. In addition, IGEL services such as acupuncture and TENS therapy have proven their worth. In TENS therapy, electrodes are attached to the painful areas, through which a stimulation current of 80 to 120 Hertz is then passed. The tingling on the skin that arises masks the pain on the one hand and causes the body to release endorphins on the other. These endorphins dock to the pain receptors. In this way, the electrical stimulation therapy can switch off pain. TENS machines are also available for home use, making them easier to use.
Relaxation techniques can also help against pain and discomfort. The effective and easy-to-learn progressive muscle relaxation according to Jacobson is recommended for this purpose. Meditation, breathing exercises, Reiki, yoga and EFT tapping are also good ways to counteract the pain and deal with post-herpetic neuralgia more calmly.
If the pain is particularly severe or has already become chronic, psychotherapeutic treatment is recommended in addition to drug therapy.
