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CurrentAetnaPolicy 0725

Post-Herpetic Neuralgia

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Defines Aetna's medical necessity and experimental/investigational determinations for therapies, procedures, and codes related to diagnosis and treatment of post-herpetic neuralgia (PHN); applies to Aetna members and providers submitting claims or prior authorization requests.

Policy Summary

PayerAetna

PolicyPost-Herpetic Neuralgia

Policy CodePolicy 0725

Change TypeNo material change

Effective DateJun 20, 2006

Last ReviewFeb 20, 2024

Next Review DateAug 8, 2024

Key ActionDocument use of first-line pharmacologic therapies (eg, gabapentin, pregabalin, TCAs, lidocaine patch, oral antivirals) before considering alternative or experimental interventions.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

~34listed experimental/investigational therapies

3+medically necessary therapy classes

B02.21-B02.29ICD-10 codes cited

06/20/2006original effective date

02/20/2024last review date

08/08/2024next scheduled review

Coverage Criteria for Post-Herpetic Neuralgia

Medically Necessary

Aetna considers the following medically necessary for PHN:

Medically necessary therapies: Use of oral antivirals, gabapentin, intrathecal, interlaminar or transforaminal epidural corticosteroids, lidocaine patch, oral opioids, pregabalin, and tricyclic antidepressants for treatment of post-herpetic neuralgia (PHN).

Listed in policy as medically necessary

Experimental / Investigational (Not Covered)

Aetna considers the following experimental and investigational for PHN because effectiveness has not been established:

Experimental/Investigational therapies: Acupuncture; angiotensin II type 2 receptor antagonists; botulinum toxin; combined nerve block and pulsed radiofrequency; combination of trigeminal ganglion and retrobulbar nerve block; cryocautery; dorsal root entry zone lesions/dorsal root ganglion destruction; epidural morphine; extracorporeal shockwave therapy; fulranumab; ganglioside GM1; intercostal nerve block; intralesional corticosteroid; intravenous antiviral therapy; intravenous ketamine; intravenous lidocaine; intravenous vitamin C; intravenous zinc sulfate; iontophoresis of vincristine; laser irradiation; narrow-band ultraviolet B; peripheral nerve stimulation; pulsed radiofrequency of the dorsal root ganglion; stellate ganglion blockade; sympathectomy; thermotherapy (including fire needle and moxibustion); topical ketamine; topical piroxicam; transcranial magnetic stimulation; transcutaneous electrical nerve stimulation (TENS); transdermal oxycodone patch; trigeminal nerve block; use of gabapentin plus low-level laser for prevention of PHN; and select pharmacotherapies including biperiden, carbamazepine, chlorprothixene, Ganoderma lucidum extract, and nicardipine.

Policy Summary

PayerAetna

PolicyPost-Herpetic Neuralgia

Policy CodePolicy 0725

Change TypeNo material change

Effective DateJun 20, 2006

Last ReviewFeb 20, 2024

Next Review DateAug 8, 2024

Key ActionDocument use of first-line pharmacologic therapies (eg, gabapentin, pregabalin, TCAs, lidocaine patch, oral antivirals) before considering alternative or experimental interventions.

SourceLink

On This Page

Enumerated in policy as investigational/not established for PHN

Efficacious and supported therapies

Covered when therapy is clinically indicated based on evidence of benefit:

Pharmacologic first-line: Use of tricyclic antidepressants, gabapentin, pregabalin, opioids and lidocaine patch are effective and should be used in the treatment of PHN.

Statement of efficacy from evidence summary

Topical capsaicin (either repeated low-dose 0.075% cream or single high-concentration 8% patch [Qutenza]) may provide pain relief for some patients; randomized trials of the 8% patch showed statistically significant pain reductions versus control and low-dose regimens showed modest benefit. Local skin reactions are common; high-concentration patch is applied for 60 minutes and may be repeated no more frequently than every 3 months as needed.

Benefit modest; local reactions common; repeat application interval per policy evidence

Corticosteroids for prevention of PHN

Not supported for prevention:

Corticosteroids during acute HZ: Randomized trials and meta-analyses provide moderate-quality evidence that corticosteroids given acutely during herpes zoster do not prevent PHN at 6 months and therefore are not effective for PHN prevention.

Five RCTs (787 participants) reviewed; no significant prevention effect

Interventional and unproven therapies

Considered unproven or equivocal:

Interventional therapies: Evidence for epidural corticosteroids, many nerve blocks, intrathecal methylprednisolone, spinal cord stimulation, and other interventional procedures is equivocal or unproven; additional randomized controlled trials are needed to establish efficacy for PHN.

Some small positive signals reported but overall insufficient high-quality evidence

Other therapies listed as unproven: Therapies such as acupuncture, TENS, several topical agents, ketamine, and various alternative approaches have not been proven effective for PHN in available trials and are described as unproven or of low/insufficient evidence in the policy.

Document lists multiple agents/procedures as not of benefit or unproven

The policy lists specific CPT and HCPCS items as examples of codes not covered for the indications in this bulletin. Examples include codes for pulsed radiofrequency of the dorsal root ganglion, neurolytic epidural injections (e.g., 62281–62282), neurostimulator implantation (e.g., 63650, 63655), trigeminal nerve injections (e.g., 64400), intercostal nerve blocks (64420–64421), stellate ganglion injection (64510), and supplies/devices for electrical stimulation such as A4595 and E0720–E0731.

HCPCS/J-code listings also call out injectable agents and device-related items not covered for PHN indications, including examples such as J0585/J0587 (botulinum toxin), J2001 (IV lidocaine), and various methylprednisolone/dexamethasone HCPCS that are noted in the document as not covered in specified contexts.

Evidence summaries in the policy cite several specific treatments evaluated in the literature and conclude that many are unproven or have limited benefit. Noted examples include acupuncture, epidural methylprednisolone, epidural morphine sulfate, and iontophoresis of vincristine, while established first-line pharmacologic treatments such as tricyclic antidepressants, gabapentin, pregabalin, lidocaine patch, and opioids are described as effective. The topical capsaicin preparations (low-dose creams and the high-concentration 8% patch) are discussed as providing modest pain relief in some trials.

Randomized and systematic-review evidence for topical lidocaine is summarized as showing statistical pain relief versus placebo in pooled trials, supporting its role among topical options for PHN management.

The document segment focuses primarily on clinical evidence syntheses and study-level findings rather than issuing standalone coverage exclusion statements. Evidence summaries report which therapies lack sufficient randomized trial support or have equivocal results; explicit policy exclusion language is provided elsewhere in the CPB (coding/exclusion lists), but the background text itself emphasizes the evidence base rather than formal coverage determinations.

The UpToDate summaries cited in the policy note that interventions such as transcutaneous electrical nerve stimulation (TENS), transcranial magnetic stimulation (TMS), and acupuncture have not been proven effective for postherpetic neuralgia according to contemporary reviews, indicating limited endorsement of these modalities in that source.

An UpToDate review referenced by the policy does not list trigeminal (Gasserian) nerve block as a therapeutic option for PHN, and a separate UpToDate overview of chronic widespread pain does not mention the capsaicin 8% patch (Qutenza) in that context. These citations indicate that trigeminal nerve block and capsaicin patch have limited or absent endorsement in those UpToDate summaries.

Multiple interventions are identified in the policy as not of established benefit or unproven for PHN. Examples explicitly described in evidence summaries include epidural methylprednisolone, epidural morphine sulfate, iontophoresis of vincristine, sympathectomy, and several topical/alternative modalities (e.g., certain lasers, topical piroxicam). The policy distinguishes these approaches from therapies that have demonstrated benefit in randomized trials (e.g., gabapentin, pregabalin, tricyclic antidepressants, lidocaine patch).

Systematic reviews and randomized trials summarized in the policy provide moderate-quality evidence that corticosteroids given during the acute herpes zoster episode do not prevent post-herpetic neuralgia at 6 months. Five randomized, double‑blind, placebo‑controlled trials (total n=787) were assessed and meta-analyses reported no significant difference between corticosteroid and control groups for the primary prevention outcome.

The excerpt reporting corticosteroid trial results presents the evidence assessment and conclusions but does not itself use an explicit phrasing such as ‘not medically necessary’ within that background text. The policy’s coverage determinations and non-coverage lists appear elsewhere in the CPB, while this section focuses on the trial data and the reviewers’ judgment that corticosteroids are ineffective for PHN prevention.

Coding (CPT, HCPCS, ICD-10)

Covered CPT CodesCPTCovered

62320	Injection(s), of diagnostic or therapeutic substance(s), interlaminar epidural or subarachnoid, cervical or thoracic
62321	Injection(s), of diagnostic or therapeutic substance(s), interlaminar epidural or subarachnoid, cervical or thoracic
62322	Injection(s), of diagnostic or therapeutic substance(s), interlaminar epidural or subarachnoid, lumbar or sacral (caudal)
62323	Injection(s), of diagnostic or therapeutic substance(s), interlaminar epidural or subarachnoid, lumbar or sacral (caudal)
62324	Injection(s), including indwelling catheter placement, continuous infusion or intermittent bolus, interlaminar epidural or subarachnoid, cervical or thoracic
62325	Injection(s), including indwelling catheter placement, continuous infusion or intermittent bolus, interlaminar epidural or subarachnoid, cervical or thoracic
62326	Injection(s), including indwelling catheter placement, continuous infusion or intermittent bolus, interlaminar epidural or subarachnoid, lumbar or sacral (caudal)
62327	Injection(s), including indwelling catheter placement, continuous infusion or intermittent bolus, interlaminar epidural or subarachnoid, lumbar or sacral (caudal)
64479	Injection(s), anesthetic agent and/or steroid, transforaminal epidural, with imaging guidance; cervical or thoracic, single level
64480	Each additional level, transforaminal epidural cervical or thoracic (add-on)

1–10 of 16

1/2

Covered HCPCS / J-CodesHCPCSCovered

J1020	Injection, methylprednisolone acetate, 20 mg
J1030	Injection, methylprednisolone acetate, 40 mg
J1040	Injection, methylprednisolone acetate, 80 mg
J1094	Injection, dexamethasone acetate, 1 mg
J1100	Injection, dexamethasone sodium phosphate, 1 mg
J1320	Injection, amitriptyline HCL, up to 20 mg
J1700	Injection, hydrocortisone acetate, up to 25 mg
J1710	Injection, hydrocortisone sodium phosphate, up to 50 mg
J1720	Injection, hydrocortisone sodium succinate, up to 100 mg
J2650	Injection, prednisolone acetate, up to 1 ml

1–10 of 16

1/2

Not Covered HCPCS / J-CodesHCPCSNot Covered

A4595	Electrical stimulator supplies, 2 lead, per month (e.g. TENS, NMES)
E0720	TENS device, two lead, localized stimulation
E0730	TENS device, four or more leads, for multiple nerve stimulation
E0731	Form-fitting conductive garment for delivery of TENS or NMES
J0133	Injection, acyclovir, 5 mg
J0190	Injection, biperiden lactate, per 5 mg
J0585	Botulinum toxin type A, per unit
J0587	Botulinum toxin type B, per 100 units

Covered ICD-10 CodesICD-10Covered

B02.21	Zoster with other nervous system involvement
B02.22	Zoster with other nervous system involvement
B02.23	Zoster with other nervous system involvement
B02.24	Zoster with other nervous system involvement
B02.25	Zoster with other nervous system involvement
B02.29	Zoster with other nervous system involvement, other

Provider Actions, Prior Authorization, and Documentation

Prior Authorization

Prior authorization not specified

Prior authorization not specified in this excerpt. The policy text and coding sections do not list any specific prior authorization requirements for procedures or drugs; providers should follow standard payer processes where applicable.

If selection criteria are met, include applicable CPT/HCPCS/ICD-10 codes on claims.
When using Qutenza (capsaicin 8% patch), document indication, area treated, number of patches, and application time.

Note

No prior authorization language present in evidence

No prior authorization language is present in the clinical evidence and background sections. These portions summarize studies, approvals, and clinical considerations but do not establish authorization triggers.

Clinical evidence (studies, reviews) is informational and does not replace formal coverage rules.
Use the Experimental and Investigational list (e.g., TENS, peripheral nerve stimulation, topical ketamine) to guide denial risk for non-covered modalities.

Prior Authorization

Prior authorization not addressed in this excerpt

Prior authorization is not addressed in this excerpt — administrative and evidence syntheses are presented without operational prior-auth rules.

Administrative policy history and review links are provided elsewhere in the document for operational rules.
Contact payer/provider relations for any site-specific prior authorization procedures.

Denial Risk

Denial risk for experimental/investigational therapies

Denial risk exists for therapies listed as experimental and investigational. Use of listed modalities without established effectiveness (see Policy: Experimental and Investigational list) may result in claim denial.

Examples of experimental/investigational therapies in this policy include: acupuncture; botulinum toxin (for PHN indication); extracorporeal shockwave therapy; peripheral nerve stimulation; pulsed radiofrequency of the dorsal root ganglion; TENS; topical ketamine; transdermal oxycodone patch; and others listed in the policy.
If proposing coverage for an experimental modality, include robust supporting literature and rationale in prior authorization/appeal documentation.

Documentation Required

Qutenza (capsaicin 8% patch) — application and documentation

Qutenza (capsaicin 8% patch) must be applied by a health care professional and requires specific documentation at the time of application.

Document the treated diagnosis/indication, anatomical area(s) treated, number of patches used (up to 4), application duration (typically 60 minutes), and date of application.
Document use of topical anesthetic or other analgesia used during application and monitoring of blood pressure for at least 1 hour post-application.
Repeat applications should be recorded (interval not more frequent than every 3 months) and rationale for repeat treatment included.

Note

Segment contains evidence syntheses and study summaries

This segment contains extensive evidence syntheses and study summaries (e.g., Cochrane reviews, randomized trials, observational studies) that inform clinical context but do not themselves create coverage rules.

Evidence summarized includes reviews and trials on topical lidocaine, capsaicin (low- and high-concentration), epidural and intrathecal corticosteroids, gabapentinoids, and interventional procedures.
When relying on interventional evidence, ensure documentation of prior conservative therapy and objective outcome measures to support medical necessity.

Documentation Required

Outcome documentation for TFEI and epidural approaches

Outcome documentation used in studies of transforaminal epidural injections (TFEI) and other epidural approaches commonly includes validated pain and function measures; documenting these on follow-up supports clinical decision-making and coverage requests.

Record baseline and follow-up pain scores (e.g., VAS, NRS) and functional measures (e.g., SF-36) at specified intervals (1 week, 1 month, 3 months, etc.).
Document response to intervention (e.g., % pain reduction) — studies cited considered <50% improvement at 1 week as predictive of progression to PHN.
Include prior conservative therapy trials and concurrent treatments in the record.

Note

Policy history and administrative links

Policy history and administrative links are available in the document footer and should be referenced for the most recent review dates and operational guidance.

Effective date: 2006-06-20; Next Review: 08/08/2024 (as noted in policy history).
Review and Definitions links are present in the policy for administrative details and should be consulted for procedural updates.

Step Therapy

Conservative/first-line therapy expectation and sequencing

Conservative/first-line therapy expectations and therapeutic sequencing are noted in the policy background: use of first-line agents is expected before considering advanced or experimental interventions.

First-line therapies specified include gabapentinoids (gabapentin, pregabalin), tricyclic antidepressants, topical lidocaine patches, and opioids where appropriate.
Document trials of and response to first-line conservative therapies before requesting coverage for interventional or experimental modalities.
Therapeutic sequencing considerations: consider add-on therapies (e.g., zinc, radiofrequency lesioning) only after insufficient response to first-line agents, and include supporting clinical data.

Step Therapy

Gabapentinoids as first-line; no formal step therapy specified

Notes regarding gabapentinoids and step-therapy: gabapentin and pregabalin are identified as first-line agents for PHN in the policy; however, no formal step therapy mandates or rules are specified in this excerpt.

Providers should document use and trial of gabapentinoids when clinically indicated, but there is no explicit payer step-therapy requirement stated here.
When gabapentinoids are ineffective or not tolerated, document rationale for alternative therapies and supporting clinical literature.

Conservative Treatment and First-Line Therapy Requirements

Expectation to use standard pharmacologic therapies prior to alternative/experimental interventions

Use of standard pharmacologic therapies is expected prior to considering alternative or experimental interventions.

Expectation of first-line therapy: Patients should have trialed established first-line pharmacologic agents for PHN — including tricyclic antidepressants, gabapentin or pregabalin, lidocaine patch, and appropriate analgesics (including opioids when clinically indicated) — prior to consideration of alternative, experimental, or interventional therapies.

Policy emphasizes established pharmacologic first-line therapies before alternative/experimental interventions

Documented use of first-line pharmacologic therapy commonly present in trials

Documented use of first-line pharmacologic therapy (gabapentinoid) is commonly present in trial populations but no explicit policy requirement is stated in this text.

Trial populations use gabapentinoids: Many clinical reports and trials described in the policy used gabapentin or pregabalin as baseline/first-line therapy when evaluating adjunctive interventions (e.g., zinc supplementation, PRF combined with gabapentin).

Documented in trial descriptions but policy does not mandate as requirement

Frequency Limits and Repeat Application Rules

Qutenza repeat application

Repeat-application intervalQutenza (capsaicin 8% patch) — patches should be reapplied no more frequently than every 3 months (repeat every 3 months or as warranted by return of pain)

Application durationPatches should be applied for 60 minutes per product insert

Number of patchesApplied to most painful skin areas using up to 4 patches

Interventional procedures and frequency limits

Interventional procedures notedTrigeminal (Gasserian) ganglion block, retrobulbar block, and pulsed radiofrequency (PRF) to dorsal root ganglion are discussed in case reports and series

Frequency limitsNo explicit frequency limits specified in the cited reports or summaries

Imaging guidanceReported procedures were performed under fluoroscopic or CT guidance in the cited case and retrospective series

Transforaminal epidural steroid injection (case report)

Reported procedureSingle-level T10 transforaminal epidural steroid injection reported in a case report for refractory PHN

Follow-up outcomePatient reported complete resolution of symptoms at 2- and 12-week follow-ups

ContextDescribed as a single procedure in the individual case report; no policy-level frequency limit provided

HCCP application frequency in studies

Observed repeat applicationsIn an observational cohort of 279 patients, mean number of HCCP applications was 4.1 per patient (1,141 total applications)

Concomitant therapy68.8% received HCCP as add-on to systemic therapy and 27.9% as first-line therapy

Adverse eventsSite reactions in 54.4% (primarily burning/pain 45.9%, erythema 30.8%); high blood pressure in 7.2%

Imaging and Procedural Guidance Requirements

Billing Rule

Fluoroscopy or CT guidance required for transforaminal epidural CPTs

Fluoroscopy or CT guidance is required for the transforaminal epidural injection CPTs (64479-64484) listed in the policy.

When billing CPTs 64479-64484, these procedures are described as performed with imaging guidance (fluoroscopy or CT).

Note

Documentation Required

Document imaging guidance for trigeminal ganglion block and CT-guided PRF cases

Reported case series and studies used fluoroscopy or CT guidance for trigeminal ganglion block, retrobulbar block, and CT-guided pulsed radiofrequency; documentation should note imaging guidance when used.

Trigeminal ganglion block case reported under fluoroscopic guidance; CT-guided PRF reported in retrospective study.

Documentation Required

Document fluoroscopic guidance for trigeminal ganglion nerve block

A reported trigeminal ganglion nerve block was performed under fluoroscopic guidance; if performed similarly, document fluoroscopic guidance in the procedure record.

Include imaging modality and targeting details in the procedure note.

Documentation Required

No mandated follow-up imaging after trigeminal/Gasserian ganglion block reported

No follow-up imaging requirement is specified after trigeminal/Gasserian ganglion block in the case report; document clinical follow-up and outcomes per standard practice.

Record clinical exams and any ophthalmic assessments performed during follow-up rather than expecting mandated imaging.

Services and Therapies Not Covered / Experimental

The CPB enumerates a list of interventions and corresponding CPT/HCPCS examples that are designated as experimental or investigational for PHN indications. Representative items called out in the coding/exclusions sections include pulsed radiofrequency of the dorsal root ganglion, peripheral nerve stimulation, TENS devices and supplies (E0720–E0731, A4595), neurolytic epidural injections (62281–62282), neurostimulator implantation (63650, 63655), trigeminal nerve injection (64400), and various HCPCS drug codes associated with investigational agents.

The policy’s not-covered/code-exclusion listings repeat items that reflect the document’s assessment of insufficient evidence for PHN, such as pulsed radiofrequency, peripheral nerve stimulation, and TENS (device and supply codes). These examples are provided in the CPT/HCPCS lists of items not covered for the indications in the CPB.

Additional interventions named in the exclusions and code tables as experimental or unproven include extracorporeal shockwave therapy (0101T), certain ultrasound-guided transforaminal injection codes (0228T–0231T), and neurolytic procedures (62281–62282), all cited in the policy’s not-covered code sections.

The HCPCS/J-code section lists specific drug and device codes that the policy identifies as not covered for PHN indications in the examples provided. These include investigational injectables such as fulranumab and ganglioside GM1, the transdermal oxycodone patch (no specific CPT), and multiple injectable agents and supplies called out in the HCPCS list.

The exclusions table further references botulinum toxin codes (J0585, J0587) and IV medication administration codes such as J2001 (IV lidocaine) among the HCPCS items enumerated in the policy’s not-covered examples for PHN indications.

Device and implant procedure codes are included among the not-covered examples; these encompass peripheral neurostimulator/implantation codes (64555–64575, 63650–63655) and supplies for electrical stimulation (A4595), which the CPB lists as not covered for the indicated PHN uses.

Intravenous lidocaine is discussed in the evidence summaries as a therapy that may provide benefit for patients refractory to other treatments, but small controlled trials have not convincingly demonstrated superiority to placebo. The policy text notes this uncertainty in the literature but does not include an explicit statement in the excerpt declaring IV lidocaine as not covered.

The policy repeats various experimental or early‑phase interventions across its exclusion lists, including agents and modalities such as iontophoresis of vincristine, narrow-band UVB/laser therapies, and several topical agents; these are cited in the CPT/HCPCS and narrative background as unproven for PHN.

Definitions and Key Terms

PHN — definition (time threshold)

Definition (time-based)Post-herpetic neuralgia (PHN) — significant pain or dysaesthesia present 3 months or more following herpes zoster

Typical presentationUsually unilateral dermatomal pain often with allodynia

Epidemiology noteMore than 5% of the elderly have PHN at 1 year after acute HZ

PHN — pathophysiology

Pathophysiology summaryPHN — chronic neuropathic pain resulting from alterations of the peripheral nervous system in areas affected by the herpes zoster virus

SymptomsPain, paresthesia, dysesthesia, hyperalgesia, and allodynia

Treatment gapPharmacologic treatments control symptoms but do not address underlying pathophysiology

Qutenza (capsaicin 8% patch)

Product identity and indicationQutenza — capsaicin 8% dermal patch approved for neuropathic pain associated with PHN

Administration settingMust be applied to the skin by a health care professional

Pre- and post-careRequires topical local anesthetic for application and monitoring for at least 1 hour post-application due to risk of BP increase

PHN — term and context

PHN term usagePost-herpetic neuralgia (PHN) — chronic neuropathic pain persisting after acute herpes zoster; term reiterated throughout the document

Clinical significancePHN is the most common complication of HZ and increases with age and immunosuppression

MeasurementDiagnosis is usually clinical based on typical unilateral dermatomal pain and rash

PRF to DRG — definition and evidence

Procedure definitionPulsed radiofrequency (PRF) to dorsal root ganglion — neuromodulation applying intermittent RF pulses to the DRG to reduce neuropathic pain

Evidence characterizationSystematic review included 28 studies (991 subjects) but overall evidence quality was low; only 5 RCTs — conclusions preliminary

Recommendation implicationCurrent PRF evidence is mainly small, low-quality studies and requires confirmation in high-quality RCTs

High-concentration capsaicin patch (HCCP / Qutenza / NGX-4010)

TerminologyHigh-concentration capsaicin patch (HCCP) — 8% topical capsaicin (Qutenza / NGX-4010) used for PHN and other peripheral neuropathic pain

Application parametersApplied by healthcare professional for 60 minutes, up to 4 patches to most painful areas; repeat interval not more frequent than every 3 months

Safety notesApplication can be painful; local anesthetic and post-application BP monitoring (at least 1 hour) recommended

Gasserian ganglion (trigeminal) block

Procedure descriptionGasserian (trigeminal) ganglion block — invasive nerve block targeting the trigeminal ganglion used for refractory trigeminal PHN

Evidence contextReported in case reports/series; associated adverse event example — corneal neurotrophic keratopathy in one case with subsequent slow nerve regeneration

GuidanceFindings from case reports are preliminary and require validation in well-designed studies

Policy Revision History

2006-06-20effective_date

Policy originally became effective.

2024-02-20last_reviewLatest

Policy underwent last review and administrative update on 02/20/2024.

2024-08-08next_review

Next scheduled policy review set for 08/08/2024.

Background and Clinical Context

Herpes zoster results from reactivation of varicella‑zoster virus in dorsal root or cranial nerve ganglia and produces a unilateral dermatomal rash with associated acute neuropathic pain. When pain or dysesthesia persists for 3 months or more after the acute infection, the condition is defined as post‑herpetic neuralgia (PHN). Incidence increases with age and immunosuppression, and PHN pain presentations commonly include burning, lancinating pain and allodynia; both peripheral and central mechanisms contribute to the chronic neuropathic state.