When does persistent shingles pain become postherpetic neuralgia?
Postherpetic neuralgia, commonly shortened to PHN, is persistent neuropathic pain in an area previously affected by shingles.
The Korea Disease Control and Prevention Agency health portal describes PHN as pain that remains for at least one month after the skin lesions have healed.
The Korean calculator represents that one-month description as a practical four-week timing check, but reaching four weeks is not a diagnosis by itself.
The pain may feel burning, stabbing, electric, or painfully sensitive to light contact from clothing or bedding.
It can continue for months or years, so a useful record covers not only pain intensity but also sleep, movement, clothing tolerance, mood, and daily function.
Current treatment aims to reduce pain and restore function rather than promise a complete cure for every patient.
What the four-week result means
Count from the date the shingles skin lesions healed, not from the first day the rash appeared.
Pain lasting less than four weeks can still need prompt care, while pain beyond four weeks still needs clinical assessment for PHN and other causes of neuropathic pain.
What this Korea-specific planner does
Tracks pain
It compares baseline and current scores on the same zero-to-ten scale and preserves improvement, no change, or worsening.
Flags combination records
It explains the Korean reimbursement distinction for gabapentin or pregabalin used with a lidocaine patch and the two-to-four-week record.
Builds a cost plan
It separates covered medicine, covered care, full-self-pay medicine, non-covered care, and only support that has already been confirmed.
The interactive English page uses a compact monthly-budget scenario because the Korean calculator is tied to local billing categories.
This deep guide preserves the exact Korean timing, cost, copayment, and reimbursement assumptions so an English-speaking patient or caregiver can interpret the Korean result correctly.
Treatment planning is individualized
PHN treatment depends on the pain pattern, age, kidney and heart health, fall risk, other medicines, and adverse effects.
The KDCA patient information identifies medicines such as gabapentin, pregabalin, and tricyclic antidepressants, while specialist care may include a local analgesic or a nerve block.
Listing an option here does not mean it is appropriate, safe, or reimbursed for a particular person.
Oral neuropathic-pain medicines
A clinician may start low and adjust gradually while monitoring sleepiness, dizziness, swelling, falls, and other adverse effects.
Do not raise, stop, or combine a prescription based on a calculator result, because tapering and dose adjustment may be medically important.
Local treatment
A lidocaine patch is applied locally, but the exact skin condition, application site, wearing time, and product instructions matter.
It should not be improvised on unhealed skin, near an eye, or on a mucous membrane without professional instructions.
Procedures and multidisciplinary care
A pain specialist may consider a nerve block or another intervention when pain remains difficult to control.
Suitability, expected benefit, repetition, and covered or non-covered billing are clinical and provider-specific decisions, not automatic outputs.
The Korean two-to-four-week combination rule
Public HIRA criteria recognize postherpetic neuralgia within the reimbursement scope for gabapentin and pregabalin when the detailed conditions are met.
When either medicine is combined with a lidocaine patch, the lower-priced medicine is generally charged in full to the patient under the published rule.
An exception may allow both medicines to be covered when one medicine was used for 2 to 4 weeks without pain improvement and that response is documented.
Korean PHN combination-treatment reimbursement checkpoints| Selected stage | Published-rule signal | How to enter the cost |
|---|
| Single medicine or another regimen | Verify product, indication, dose, and record | Copy the covered and full-self-pay split from the prescription |
| Early combination | Lower-priced medicine may be fully patient-paid | Put that amount in the full-self-pay medicine field |
| Combination after documented nonresponse | Covered combination may be reviewed after 2 to 4 weeks | Move only the amount actually billed as covered into the covered field |
Documentation is not automatic approval
Selecting the documented stage does not automatically convert a bill to covered care.
The actual drug, dose, duration, clinical response, medical record, claim, and HIRA review remain controlling, so the calculator never reclassifies a cost on its own.
Ordinary Korean copays and the narrow V170 option
National Health Insurance Act Article 44 establishes patient cost sharing, and Enforcement Decree Article 19 directs the detailed amounts to Annex 2.
The planner uses a 30% prescription-pharmacy rate and simplified outpatient rates of 30% at a clinic, 40% at a hospital, 50% at a general hospital, and 60% at a tertiary hospital.
The tertiary-hospital percentage is only a comparison estimate because the actual structure includes the full consultation fee plus 60% of other covered outpatient charges.
Patient-share assumptions used by the PHN planner| Coverage selection | Covered medicine | Covered visit or procedure |
|---|
| Ordinary NHI | 30% | 30% / 40% / 50% / 60% |
| Confirmed B02.2† / G63.0 / V170 related care | 10% | 10% |
| Uncovered or full self-pay | 100% | 100% |
PHN does not automatically mean a 10% copay
The May 1, 2026 special-case notice lists postherpetic polyneuropathy with the dagger code B02.2†, manifestation code G63.0, and special code V170.
Use the 10% option only when registration under that code combination has been confirmed and the current covered service is accepted as related care.
Ordinary PHN, an unregistered case, unrelated care, full-self-pay medicine, and non-covered services do not become 10% merely because pain followed shingles.
Exact cost formulas
Enter the gross covered amount before patient cost sharing, then keep full-self-pay medicine and non-covered care separate.
The calculation subtracts only a support or reimbursement amount that the user has already confirmed and never allows that support to exceed the patient cost for the month.
covered medicine patient cost = round(monthly covered medicine × medicine copay rate)
covered care total = covered care per visit × visits per month
covered care patient cost = round(covered care total × care copay rate)
full-self-pay and non-covered cost = full-self-pay medicine + non-covered care per visit × visits
monthly patient cost before support = the three patient-cost categories added together
monthly support applied = min(confirmed support, patient cost before support)
plan net patient cost = monthly net patient cost × treatment months
The estimated NHI share is the gross covered amount minus the simplified patient share for covered medicine and covered care.
It is not a claim statement and does not include item-level rounding, selective benefits, special pharmacy rules, inpatient care, or another reduction program.
Worked six-month example
Assume ordinary NHI at a hospital outpatient department, KRW 120,000 in gross covered medicine each month, and KRW 30,000 in full-self-pay medicine each month.
Also assume two visits per month, KRW 50,000 in gross covered care and KRW 20,000 in non-covered care per visit, six treatment months, and KRW 10,000 in confirmed monthly support.
These are transparent teaching inputs, not official average PHN prices or a hospital quote.
Worked PHN cost example using ordinary hospital outpatient copays| Calculated item | Formula | Result |
|---|
| Covered medicine patient cost | 120,000 × 30% | KRW 36,000 |
| Covered care patient cost | 50,000 × 2 × 40% | KRW 40,000 |
| Full-self-pay and non-covered | 30,000 + 20,000 × 2 | KRW 70,000 |
| Monthly cost before support | 36,000 + 40,000 + 70,000 | KRW 146,000 |
| Monthly net patient cost | 146,000 - 10,000 | KRW 136,000 |
| Six-month net patient cost | 136,000 × 6 | KRW 816,000 |
| Six-month estimated NHI share | 144,000 × 6 | KRW 864,000 |
How the pain-change result works
The point change is the baseline score minus the current score, and the percentage is that change divided by the baseline score.
A change from 8 to 5 is a three-point or 37.5% improvement, while a change from 5 to 7 is a negative two-point or -40% change and is shown as worsening.
If the baseline score is zero, the percentage is unavailable because division by zero would be misleading.
point change = baseline pain - current pain
change rate (%) = point change ÷ baseline pain × 100
- Use the same zero-to-ten scale at a similar time of day
- Record sleep, clothing contact, walking, work, and household activity as well as intensity
- Record medicine names, times, missed doses, adverse effects, and any falls
- Do not treat the percentage as proof that one medicine caused the change
A lower score does not independently justify stopping or reducing a medicine, and a higher score does not determine the next prescription.
Bring the trend to the treating clinician so benefit, function, adverse effects, and safety can be considered together.
Step-by-step use of the Korean calculator
- Enter the number of weeks that pain has continued after the shingles lesions healed
- Enter baseline and current pain using the same zero-to-ten scale
- Select single or other treatment, early gabapentin or pregabalin plus lidocaine, or combination after a documented two-to-four-week nonresponse
- Select ordinary NHI, confirmed V170 related care, or uncovered and full-self-pay care
- Copy gross covered medicine, full-self-pay medicine, gross covered care, and non-covered care from the prescription or provider quote
- Enter visits per month, planning months, and only support already confirmed in writing
- Read any urgent-symptom alert before reviewing the budget and reimbursement guidance
Numeric fields preserve an editable draft while typing and commit a clamped value when focus leaves the field or Enter is pressed.
This prevents a positive minimum from making a field impossible to clear temporarily and supports comma-formatted Korean won inputs.
Useful planning scenarios
Preparing for a first pain-clinic visit
Record the healing date, affected area, pain score trend, sleep disruption, and prior medicines in one place.
This does not replace a history, but it can reduce uncertainty about dates and treatment response during the consultation.
Checking a new combination prescription
Ask whether the lower-priced medicine is shown as covered, full self-pay, or another claim category when a lidocaine patch is added.
If the record documents no improvement after 2 to 4 weeks, ask whether that exception has actually been applied to the current claim.
Comparing a longer budget
Change visit frequency, an itemized non-covered quote, or the planning period to compare cash-flow scenarios.
Cost alone should not determine medicine choice, procedure frequency, or whether treatment is medically necessary.
Symptoms that should take priority over cost planning
Shingles can involve the eye, ear, facial nerve, or other neurologic structures, and a new systemic illness can require prompt assessment.
Contact a medical service promptly for the following changes, and use local emergency guidance when symptoms are sudden or severe.
Eye or vision symptoms
Eye pain, a new rash near the eye, blurred vision, or another visual change needs prompt assessment.
Ear or facial symptoms
Blisters near an ear, hearing change, severe vertigo, or new facial weakness needs prompt assessment.
New weakness
New limb weakness, paralysis, difficulty walking, or a rapidly changing neurologic symptom needs prompt assessment.
Widespread or systemic illness
A spreading new blistering rash, fever, confusion, or a marked decline in general condition needs prompt assessment.
The checkboxes are not a screening examination and an unchecked box does not rule out a complication.
Any new or worrying symptom can justify medical advice even when it is not listed here.
Frequently asked questions
Does exactly four weeks confirm PHN?
No.
Four weeks is the calculator approximation of the KDCA one-month description, while diagnosis still depends on the affected area, pain pattern, examination, and exclusion of other causes.
Is one medicine always non-covered when gabapentin and a lidocaine patch are combined?
The published criteria generally make the lower-priced medicine fully patient-paid, but they include a possible covered-combination exception after documented nonresponse to one medicine for 2 to 4 weeks.
Full self-pay under a reimbursement rule is not necessarily the same legal billing category as a non-covered service, so copy the prescription classification rather than guessing.
Can every person with PHN select the V170 10% option?
No.
The option is limited to confirmed registration for postherpetic polyneuropathy under B02.2† with G63.0 and V170, and to the related covered care accepted under that registration.
Does the result deduct the annual out-of-pocket ceiling?
No.
The ceiling depends on eligible covered patient payments across the calendar year and the applicable income tier, while non-covered and excluded charges cannot simply be added to the ceiling base.
Is private indemnity insurance estimated automatically?
No.
Policy generation, outpatient deductibles, exclusions, limits, documentation, and prior payments vary, so only an insurer-confirmed payment should be entered as support.
Can a good pain-change percentage justify reducing medicine?
No.
Some medicines need supervised dose changes or tapering, so bring the pain, function, and adverse-effect record to the prescriber before changing treatment.
Official sources and update triggers
- KDCA National Health Information Portal shingles guidance updated May 11, 2026
- National Health Insurance Act Article 44 and Enforcement Decree Article 19 with Annex 2, checked July 22, 2026
- Detailed Standards for Applying Drug Benefits under MOHW Notice No. 2026-133, effective July 1, 2026
- HIRA public reimbursement criteria for gabapentin, pregabalin, and lidocaine patches
- Special Copayment Calculation Criteria under MOHW Notice No. 2026-101, effective May 1, 2026
Recheck the calculator when the combination-treatment exception, ordinary outpatient rates, V170 code combination, or special-case copay changes.
The actual Korean prescription, itemized provider bill, current HIRA criteria, and insurer decision always take priority over this planning result.
Recalculate with the actual prescription and pain record
Replace the teaching amounts with the real covered, full-self-pay, and non-covered categories from the Korean documents.
Take the result and the two-to-four-week response record to the treating clinician or billing desk to confirm medical need, safety, and actual reimbursement.