Postherpetic Neuralgia Treatment in Delhi, India

Postherpetic neuralgia, in simple terms, means nerve pain post herpes zoster or shingles. 

It is a painful condition affecting skin and nerve fibres. It is the most common complication of shingles. If you experience pain at the site of shingles even after the rash has resolved, it is called postherpetic neuralgia (PHN).

Postherpetic Neuralgia Causes

If you’ve had chickenpox, the varicella-zoster virus (the virus that causes chickenpox) remains in your body for a lifetime, and sometimes it gets reactivated in older age or if you develop a weak immune system, resulting in shingles, which appears as blisters and rash on one side of the body, mostly at the trunk area. In about 20% of patients, the pain remains for weeks, months, or even years even after the rash has resolved. This is called postherpetic neuralgia. 

It is caused due to damaged nerves at the site of shingles rash, affecting their structure and functioning. These nerves send improper signals to the brain, causing exaggerated pain responses.

Postherpetic Neuralgia Symptoms

Signs and symptoms of postherpetic neuralgia are generally limited only to the area where shingles had appeared and include:

• Severe, burning, jabbing-kind of pain at the site, lasting for more than three months.
• Hypersensitivity to touch. Sometimes, even the touch of clothing to that area is intolerable.
• Itching and numbness around the area of the prior rash.
• Slight fever and malaise.

Postherpetic Neuralgia Diagnosis

No diagnostic tests are required to confirm the diagnosis of postherpetic neuralgia.  It is diagnosed based on the symptoms, physical examination, and history of shingles. If you recently had an outbreak of shingles rash and are experiencing pain in the same area even after the resolution of the rash, you most likely have postherpetic neuralgia.

Postherpetic Neuralgia Treatment

A single treatment modality is usually not sufficient to relieve postherpetic neuralgia, so a combination of medications can be prescribed, including:

Creams

Topical creams containing pain-relieving medications like lidocaine or capsaicin provide temporary pain relief.

Oral pain medications

Painkillers such as acetaminophen or NSAIDs like ibuprofen, etc. are prescribed to relieve acute pain and inflammation.

For severe pain, these may be prescribed:

Anti-seizure medications

Anticonvulsant drugs such as gabapentin control the abnormal electrical activity caused by damaged nerves, relieving pain from herpetic neuralgia.

Antidepressants

They are given in small doses to affect brain chemicals that alter how the body interprets pain. This is done to control postherpetic neuralgia.

Opioid painkillers

In rare cases of severe pain, opioid painkillers like tramadol, oxycodone, or morphine are given, but CDC guidelines restrict opioids for non-cancer-related pain because they are addictive.

Risk Factors of Postherpetic Neuralgia

Certain people are at higher risk of developing postherpetic neuralgia. These include:

• Age above 50: If you develop shingles after the age of 50, there are more chances of developing postherpetic neuralgia.
• Severe shingles: If you had a severe shingles outbreak, you are at a higher risk of developing postherpetic neuralgia.
• Weak immune system: Weakened immune system reactivates dormant varicella-zoster virus. The immune system gets weak by age, by certain chronic conditions like AIDS, by receiving chemotherapy for cancer treatment, immunosuppressive medications after organ transplant, etc.
• Delay in shingles treatment: Consult a doctor and start antiviral therapy within 72 hours of the appearance of the shingles rash. If the therapy is delayed, the risk of postherpetic neuralgia increases.
• Symptoms before shingles rash: If you had symptoms like pain, itching, numbness, or tingling at the site before shingles rash, you most probably have postherpetic neuralgia symptoms post-resolution of the rash.

Complications of Postherpetic Neuralgia

The pain and discomfort caused by postherpetic neuralgia can be disabling and interfere with daily life. The complications of PHN may include:

• Difficulty sleeping.
• Fatigue.
• Decreased appetite.
• Poor concentration.
• Depression.

Postherpetic Neuralgia Prevention

• Vaccination: Vaccination is an effective measure to prevent shingles and PHN. FDA has approved a recombinant herpes-zoster vaccine, Shingrix, for people ages 50 and above to prevent shingles. It is given in 2 doses, 2 to 6 months apart, and is 90% effective in preventing shingles and PHN. This vaccine protects for at least 4 years.

  If you’ve never had chickenpox, get yourself vaccinated with the chickenpox vaccine. This will prevent the varicella-zoster virus from getting into your body, and thus you will not have a chance of developing shingles or PHN.

  The vaccine, Shingrix, is recommended even if you have had shingles, to prevent postherpetic neuralgia.

• Initiation of Shingles treatment within 72 hours: Getting early treatment for shingles also reduces the risk of getting PHN. Antiviral therapy needs to be initiated within 2 to 3 days of developing the rash. Thus, if you think you have shingles, visit your doctor promptly.

Epidemiology of Postherpetic Neuralgia

• Postherpetic neuralgia is most commonly seen in patients of age 50 and above.
• Women seem to be more prone to PHN than men. 
• Individuals with chronic conditions like diabetes, or those with conditions that weaken the immune system, such as HIV and cancer, are more likely to develop PHN.

Prognosis of Postherpetic Neuralgia

There is no cure for postherpetic neuralgia, but pain and other symptoms can be effectively managed with medications. In most cases, the pain resolves within 1 to 3 months, though it is not uncommon to last for a year or more.

Natural Progression of Postherpetic Neuralgia

For most people, postherpetic neuralgia resolves over time in about 3 months, though it might last for several years in some patients. Treatment should be taken for the management of pain and other symptoms. If left untreated, postherpetic neuralgia can become a severe and debilitating disease.

Pathophysiology of Postherpetic Neuralgia

Postherpetic neuralgia is caused due to damage to nerve fibres at the site of shingles rash. These nerve fibres can no longer transmit messages from the skin to the brain as they usually do. The messages now become exaggerated and confused, resulting in a chronic, sharp pain that can last for months or even years.