Understanding Postherpetic Neuralgia and Treatment Options
Simon Says, MD/PhD
simonrdownes.com
Important note
Even if you have received both recommended shingles vaccine injections, you can still develop shingles. The vaccine significantly reduces the risk and severity, but it does not provide complete protection.
What is allodynia after shingles?
After an episode of shingles (herpes zoster), some individuals develop persistent nerve pain known as postherpetic neuralgia (PHN). One of the most distressing symptoms is allodynia, where even light touch, clothing, or temperature changes cause significant pain.
This occurs because the varicella zoster virus damages peripheral nerves, leading to abnormal signaling and heightened sensitivity.
Why does this happen?
Following shingles, nerve fibers may become:
- Damaged or inflamed
- Hyperactive and misfiring
- Over responsive to normal stimuli
This results in:
- Burning or stabbing pain
- Electric shock like sensations
- Pain triggered by normally non painful stimuli
Clinical perspective
In older adults, shingles may be preceded by a prodrome of pain before the rash appears. For example, a patient in her early seventies may experience shoulder or chest discomfort for days to weeks prior to the outbreak. This can sometimes mimic cardiac or musculoskeletal conditions.
When the rash appears along a thoracic dermatome, the diagnosis becomes clearer. However, symptoms such as leg numbness may occasionally occur and are not always fully explained. These atypical features highlight the importance of careful evaluation and follow up.
Even when antiviral treatment such as acyclovir is started later in the course, patients may still go on to develop postherpetic neuralgia and allodynia.
Treatment Options
Management focuses on symptom control, since there is no single cure for nerve injury.
1. Traditional evidence based medical treatments
First line therapies
- Gabapentin or pregabalin
These medications calm overactive nerve signals and are often first choice - Tricyclic antidepressants such as amitriptyline or nortriptyline
These modify how pain is processed in the nervous system - Topical lidocaine patches 5 percent
Especially useful for localized areas of allodynia
Second line or adjunct therapies
- Capsaicin cream or high dose patch
Works by desensitizing pain fibers over time - Opioids such as tramadol
Used cautiously in severe cases due to risk of dependence - NSAIDs or acetaminophen
Usually limited benefit for neuropathic pain
Interventional and advanced therapies
- Nerve blocks
- Epidural steroid injections
- Spinal cord stimulation
- Peripheral nerve stimulation
- Botulinum toxin injections
2. Non traditional and complementary approaches
Physical and device based therapies
- TENS therapy
- Acupuncture or electroacupuncture
Lifestyle and self care strategies
- Heat or cold application depending on tolerance
- Gentle exercise such as walking or tai chi
- Sleep optimization
- Anti inflammatory diet including omega 3 fatty acids
Mind body approaches
- Meditation and mindfulness
- Cognitive behavioral therapy
Natural and supportive approaches
- Essential oils such as lavender or peppermint
- Stress reduction practices
Prevention and important considerations
- Early antiviral treatment within 72 hours of rash onset can reduce severity
- The shingles vaccine significantly lowers the risk of developing shingles and postherpetic neuralgia
However, shingles can still occur even after full vaccination, although symptoms are often milder.
Key takeaways
- Allodynia after shingles is a neuropathic pain condition caused by nerve injury
- First line treatments include gabapentin, antidepressants, and lidocaine patches
- More advanced therapies are available if symptoms persist
- Complementary approaches can improve comfort and quality of life
- Vaccination reduces risk but does not completely eliminate the possibility of shingles
Simon R. Downes 