ModifiedUnitedHealthcarePolicy CSO69LA.O

Light and Laser Therapy (for Louisiana Only)

Policy governing medical necessity and coverage of light and laser therapies for dermatologic conditions for UnitedHealthcare members in Louisiana.

Policy Summary

PayerUnitedHealthcare

PolicyLight and Laser Therapy (for Louisiana Only)

Policy CodePolicy CSO69LA.O

Change TypeCoverage and coding revisions

Effective DateJanuary 1, 2025

Next Review DateN/A

Key ActionUse updated coding (added 17999 and 96999; removed 17380) and document prior conservative therapy when requesting coverage for ablative fractional laser for hypertrophic burn scars.

SourceLink

POLICY UPDATE CHANGES

Replaced language that laser hair removal is proven and medically necessary for pilonidal sinus disease treated with surgery for debridement/abscess with language tying medical necessity to surgery for control of hair regrowth.

Revised list of conditions for which light and laser therapy is unproven and not medically necessary; added onychomycosis.

Added statement that excimer laser therapy is considered cosmetic and not medically necessary for treatment of vitiligo.

Applicable CPT coding changes: added CPT 17999 for laser hair removal and removed CPT 17380; added CPT 96999 for excimer laser therapy.

Updated Description of Services, Clinical Evidence, FDA, and References sections to reflect current information.

01/01/2025Effective date

LouisianaGeographic scope

23.2% vs 33.2%Pilonidal recurrence RCT

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

Cochrane RCTs for scars

OnychomycosisAdded as unproven

Coverage Criteria and Clinical Indications

inv-01: Medically Necessary Indications

Covered when ALL of the following are met (by specific indication):

Pulsed dye laser (PDL) for vascular lesions: PDL therapy is proven and medically necessary for treating port-wine stains and cutaneous hemangioma/hemangiomata.

Laser hair removal for pilonidal disease: Laser hair removal is proven and medically necessary for the treatment of pilonidal sinus disease that has been or is being treated with surgery for control of hair regrowth.

Fractional ablative laser for hypertrophic burn scars: Fractional ablative laser fenestration (e.g., CO2, Er:YAG) of hypertrophic burn scars is proven and medically necessary when both of the following are met: the individual has tried and failed at least one conventional treatment and the burn scar is causing functional impairment (limiting range of motion) and the treatment can be reasonably expected to improve the functional impairment.failed >=1 conventional treatment

Examples of conventional treatments: hypoallergenic paper tape, pressure garments, silicone kits with gel sheeting.

inv-02: Not Medically Necessary / Cosmetic

Not medically necessary / unproven for the following when used to treat these conditions:

Unproven / Not Medically Necessary: Light and laser therapies (including but not limited to intense pulsed light; light phototherapy; photodynamic therapy; Nd:YAG; excimer; and pulsed dye laser) are unproven and not medically necessary for treating onychomycosis, acne vulgaris, rhinophyma, and rosacea due to insufficient evidence of efficacy.

Excimer for vitiligo: Excimer laser therapy is considered cosmetic and not medically necessary for treatment of vitiligo.

Explicitly stated as cosmetic / not medically necessary.

inv-03: Coverage considerations by condition

Evidence-informed considerations (not explicit policy rules) derived from document:

Infantile hemangioma (IH) laser use: PDL and other lasers have been studied for infantile hemangiomas; PDL is the most-studied modality and may be effective for superficial or residual/refractory lesions, but the overall strength of evidence ranges from insufficient to low — consult a hemangioma specialist and consider prior beta-blocker therapy when applicable.

Based on systematic reviews and meta-analyses noting heterogeneous protocols and limited comparative data.

Pilonidal disease laser epilation: Laser epilation has randomized and observational evidence showing reduced recurrence when added to standard care; consider prior standard care education and planned number/type of laser sessions when evaluating clinical use.

Minneci et al. RCT reported 1-year recurrence 23.2% with laser epilation vs 33.2% with standard care; systematic reviews report high primary healing rates but heterogenous methods.

Hypertrophic/keloid burn scars: Ablative fractional CO2 and other fractional ablative lasers show improvements in validated scar scales and objective measures in meta-analyses and cohort studies, but evidence quality is low to very low and heterogeneity in protocols and outcomes limits certainty about optimal timing, number of sessions, and comparative effectiveness.

inv-04: Hypertrophic Burn Scar Treatment with Ablative Fractional CO2 and Other Lasers

Evidence on laser treatment for hypertrophic burn scars shows multiple observational studies, systematic reviews and meta-analyses with generally positive but heterogeneous and often low-certainty results.

Evidence summary: Systematic reviews, meta-analyses and cohort studies report statistically significant improvements in validated scar scores (VSS, POSAS), scar thickness by ultrasound, pigmentation, vascularity, pliability and height after ablative fractional CO2 (AFL-CO2) and other ablative fractional lasers.

Quality of evidence often low or very low; heterogeneity and risk of bias across studies noted.

Reported benefits: Studies report objective improvements in elasticity and reductions in scar thickness, with high patient satisfaction reported in some single-center cohorts and meta-analyses noting meaningful VSS/POSAS improvements.

Examples: meta-analyses and systematic reviews included hundreds of patients and reported significant improvements but with variable protocols and follow-up.

Limitations: The evidence is limited by small single-center studies, lack of randomization in many cohorts, heterogeneity in laser systems and protocols, and risk of bias; Cochrane and other reviews rate certainty as very low for many comparisons and call for standardized outcome measures and higher-quality trials.

inv-05: Acne Vulgaris — Light and Laser Therapies

Multiple RCTs, systematic reviews and meta-analyses evaluate various light-based therapies for acne with mixed quality and heterogeneous methods.

Evidence summary: Numerous RCTs and systematic reviews identify many light- and laser-based interventions for acne, but methodological limitations, heterogeneity in light sources, dosing, and outcomes mean overall evidence quality ranges from moderate to very low; some modalities (notably PDT and photochemical therapies) show promise, particularly as adjuncts.

NICE network meta-analysis included ~179 RCTs but judged many at moderate-to-very-low quality.

Efficacy findings: PDT and some photochemical therapies can reduce inflammatory lesion counts; IPL, fractional CO2, Nd:YAG and diode lasers show variable efficacy in small trials; blue-light studies show inconsistent results.

Heterogeneous outcomes and short follow-up periods limit conclusions.

Safety: Across acne light/laser studies, adverse events are generally mild (erythema, pain, transient burning); retrospective data suggest non-ablative lasers may be used safely with isotretinoin in some settings, but study designs limit certainty of safety conclusions.

inv-06: Conditional coverage for PDT and limited coverage stance for other light/laser therapies

Covered when ALL of the following are met (implied from guideline recommendations and evidence uncertainty):

General prerequisites: Patient is an adult (>=18) when considering photodynamic therapy (PDT) for acne; adequate trials of standard topical and systemic therapies have failed, were not tolerated, or are contraindicated.

Reflects NICE conditional recommendation and AAD statement regarding insufficient evidence for routine device use.

Modality-specific evidence: PDT using ALA or MAL with an appropriate light source has limited/moderate evidence as an adjunctive therapy for acne; other light/laser modalities lack sufficient high-quality evidence to recommend routine use and should be considered only when conventional therapies are not appropriate.

Based on NICE guidance and systematic reviews noting heterogeneity and limited trial quality.

inv-07: Coverage considerations for device-based dermatologic therapies

Evidence-based findings and society guidance describing when device-based treatments may be considered

Device options studied: Multiple laser and light modalities (KTP, PDL, LPAL/LPAN, Nd:YAG, IPL, DPL, Er:YAG, CO2, excimer, NB-UVB) have been studied and may be appropriate for specific disease features such as erythema/telangiectasia in rosacea, tissue debulking in phymatous rosacea/rhinophyma, and repigmentation in vitiligo.

Evidence comes from small RCTs, observational studies and society consensus statements with variable quality.

Rosacea: device use for persistent erythema/telangiectasia: PDL, KTP, IPL and related devices have evidence showing improvement in persistent central facial erythema and telangiectasia; comparative trials show similar efficacy for some devices though secondary symptom responses and adverse event profiles vary.

Professional guidance (AARS, NRS) supports device use but notes limited-quality evidence.

Phymatous rosacea/rhinophyma: Ablative lasers (CO2, Er:YAG), tangential excision, electrosurgery or dermabrasion are used for established phymatous disease; limited trial data and expert opinion support ablative/surgical approaches for severe disease.

inv-08: Laser Hair Removal — Medical Necessity

Policy-level coverage stance and major criteria updates

Laser hair removal for pilonidal disease: Laser hair removal is proven and medically necessary when used for treatment of pilonidal sinus disease that has been or is being treated with surgery for control of hair regrowth.

Revised policy language ties medical necessity to surgery for control of hair regrowth rather than debridement/abscess procedures.

inv-09: Not Medically Necessary / Unproven Indications

Not medically necessary / unproven indications

Excimer laser for vitiligo: Excimer laser therapy is considered cosmetic and not medically necessary for treatment of vitiligo.

Explicitly added in the policy revision.

Onychomycosis and other conditions: Onychomycosis was added to the list of conditions for which treatment with light and laser therapy is unproven and not medically necessary.

Policy revision updated the list of unproven/not medically necessary conditions to include onychomycosis.

Other low-certainty indications: For indications with very low or insufficient evidence (for example, many laser and light interventions for hypertrophic/keloid scars and some acne modalities), routine coverage may be considered not medically necessary without stronger supportive evidence or documented failure of conventional therapies.

Cochrane and other reviews describe very low-certainty evidence for many scar-related comparisons.

Coding clarification: viral warts and plantar warts are not vascular proliferative lesions. Laser therapy for warts must not be billed using CPT codes 17106, 17107, or 17108; reporting these vascular lesion codes for wart treatment may result in coding or coverage denial.

Hypertrophic and keloid scars: the available systematic reviews and trials provide very low‑certainty evidence for routine laser use. Because benefit is uncertain and study quality is limited, routine coverage of laser treatments for hypertrophic or keloid scars may be excluded or require strong clinical justification and documentation.

Evidence summary: a 2022 Cochrane review concluded there is insufficient evidence to support or refute the effectiveness of various laser therapies for hypertrophic and keloid scars, citing small RCTs, heterogeneity, short follow‑up, and very low certainty of results.

Onychomycosis, rosacea, and rhinophyma: guideline reviews and evidence assessments report insufficient quantity and quality of evidence to recommend light or laser therapies as routine treatments for these conditions; therefore these indications are considered unproven for standard coverage absent stronger evidence or specific combination‑therapy data.

Vitiligo — disease modification: published studies of excimer laser focus on repigmentation outcomes and do not demonstrate alteration of the underlying autoimmune disease process. Current evidence is insufficient to conclude excimer therapy changes vitiligo disease trajectory.

Excimer laser therapy for vitiligo is explicitly designated as cosmetic and not medically necessary in this policy; claims for excimer laser to treat vitiligo may be denied on that basis.

Multiple listed modalities (IPL, phototherapy, PDT, Nd:YAG, excimer, PDL and others) are identified in the policy as unproven and not medically necessary for certain conditions (including onychomycosis, acne vulgaris, rhinophyma, and rosacea) due to insufficient evidence of efficacy.

The policy reiterates the excimer laser exclusion for vitiligo: excimer therapy is treated as a cosmetic, not medically necessary intervention for vitiligo and therefore is not covered.

Use of lasers for hypertrophic and keloid scars is supported only by studies with very low‑certainty evidence; benefits observed in small trials and meta‑analyses are inconsistent and limited by risk of bias, heterogeneity, and short follow‑up, leaving clinical benefit uncertain.

When high‑quality evidence is lacking or rated very low, such as many laser and light interventions for scars and acne, the policy treats these indications as potentially not medically necessary until stronger evidence is available; payers may require additional documentation or deny coverage based on insufficient evidence.

Overall evidence landscape: most light and laser therapies lack high‑quality, long‑term evidence of effectiveness. The notable exception is conditional photodynamic therapy (PDT) for adults with moderate to severe acne after failure or intolerance of standard treatments; other modalities generally remain unsupported for routine coverage.

Multiple authors and reviews note limited study sizes, heterogeneous devices/protocols, and short follow‑up across trials of laser and light therapies. While these sources discuss potential benefits, they do not uniformly assert coverage and do not themselves constitute explicit policy determinations of medical necessity.

Light and laser therapy for onychomycosis is specifically identified in the policy as unproven and not medically necessary, reflecting mixed study results, unclear optimal regimens, and lack of evidence for prevention of medical complications.

Coding and Procedure Codes

Procedure / Unlisted codesCPT | HCPCS

17106	Destruction of cutaneous vascular proliferative lesions (e.g., laser technique); less than 10 sq cm
17107	Destruction of cutaneous vascular proliferative lesions (e.g., laser technique); 10.0 to 50.0 sq cm
17108	Destruction of cutaneous vascular proliferative lesions (e.g., laser technique); over 50.0 sq cm
96999	Unlisted special dermatological service or procedure
*0479T	Fractional ablative laser fenestration of burn and traumatic scars for functional improvement; first thereof
*0480T	Fractional ablative laser fenestration of burn and traumatic scars for functional improvement; each additional 100 cm2, or each additional 1% of body surface area of infants and children, or thereof (List separately in addition to code for primary procedure)
17999	Unlisted procedure, skin, mucous membrane and subcutaneous tissue

Diagnosis codes referencedICD-10

D18.00	Hemangioma unspecified site
D18.01	Hemangioma of skin and subcutaneous tissue
I78.0	Hereditary hemorrhagic telangiectasia
I78.1	Nevus, non-neoplastic
Q82.5	Congenital non-neoplastic nevus
Q85.89	Other phakomatoses, not elsewhere classified
L90.5	Scar conditions and fibrosis of skin
L91.0	Hypertrophic scar
L05.01	Pilonidal with abscess cyst
L05.02	Pilonidal sinus with abscess

1–10 of 12

1/2

FDA 510(k) device clearances referenced (no procedural CPT/HCPCS codes listed)mixed

No codes listed

Laser Hair Removal Applicable CodesCPT

17999	Unlisted procedure, skin, mucous membrane and subcutaneous tissue (used for laser hair removal and other unlisted procedures)
17380	CPT removed for Laser Hair Removal (removed per policy history)

Excimer Laser Therapy Applicable CodesCPT

96999

Unlisted special dermatological service or procedure (Excimer Laser Therapy listed)

Hypertrophic burn scar additional unit — coding threshold (0480T)

Threshold descriptionEach additional 100 cm2 or each additional 1% body surface area (report with HCPCS code *0480T).

Primary code referenced*0479T — Fractional ablative laser fenestration of burn and traumatic scars for functional improvement; first thereof (primary procedure).

Billing note*0480T is listed 'in addition to' the primary fractional ablative laser code and should be reported per additional unit as described.

State fee-schedule noteCodes labeled with an asterisk may not be on the State of Louisiana Medicaid Fee Schedule and therefore may not be covered by the State program.

Provider Requirements, Prior Authorization, and Documentation

Billing Rule

Provider Actions and Coding Alerts

Provider-action / billing-rule / denial-risk highlights for laser and light therapies. Use these items to prepare prior authorization requests, clinical documentation, and correct coding to avoid claim denials or delays.

Procedure codes listed for reference: CPT 17106-17108 (destruction of cutaneous vascular proliferative lesions), CPT 17999 (unlisted procedure, skin), HCPCS *0479T/*0480T (fractional ablative laser fenestration for burn/traumatic scars — note: asterisked codes may not be on some state fee schedules), CPT/HCPCS 96999 (unlisted dermatologic service — excimer laser), and CPT 17999 (laser hair removal/unlisted skin procedure).
Coding clarification: Viral or plantar warts are NOT vascular proliferative lesions; do not report wart laser therapy with CPT codes 17106-17108.
Laser hair removal coding/prior authorization: CPT 17999 was added for laser hair removal; CPT 17380 was removed. Ensure prior authorization and claims use current applicable codes.
Coding change — excimer laser: CPT 96999 added as an applicable code for excimer laser therapy. Incorrect or outdated coding may risk denial or misprocessing.

Background, Definitions, and Clinical Context

This policy summarizes indications, clinical rationale, and the evidence base for various light and laser therapies across dermatologic conditions, providing the basis for covered, not‑covered, and conditional stances.

Light therapy / Photodynamic therapy (PDT) — definition and description

DefinitionLight therapy: exposure to nonionizing radiation (phototherapy, IPL, lasers) used for therapeutic benefit; Photodynamic therapy (PDT) combines a topical photosensitizer (e.g., ALA or MAL) with an activating light source (red, blue, IPL).

Common light sourcesRed light, blue light, IPL, targeted phototherapy (e.g., excimer), and various lasers (PDL, diode, Nd:YAG).

Typical clinical usesPDT has been evaluated primarily for acne vulgaris as an adjunctive therapy; other light modalities are studied across dermatologic conditions with variable evidence.

Evidence summarySystematic reviews and RCTs show heterogeneous results; PDT (ALA or MAL + light) has shown lesion reduction in multiple trials but optimal protocols vary.

Policy Revision History and Changes

2025-01-01policy_revisionLatest

Revised coverage rationale: clarified laser hair removal medical necessity for pilonidal sinus disease to require surgery for control of hair regrowth; updated list of conditions considered unproven/not medically necessary (added onychomycosis); added that excimer laser therapy is cosmetic and not medically necessary for vitiligo; operational coding updates added CPT 17999 and 96999 and removed CPT 17380; Supporting sections (Description of Services, Clinical Evidence, FDA, References) updated.

Policy Summary

PayerUnitedHealthcare

PolicyLight and Laser Therapy (for Louisiana Only)

Policy CodePolicy CSO69LA.O

Change TypeCoverage and coding revisions

Effective DateJanuary 1, 2025

Next Review DateN/A

Key ActionUse updated coding (added 17999 and 96999; removed 17380) and document prior conservative therapy when requesting coverage for ablative fractional laser for hypertrophic burn scars.

SourceLink

On This Page

Cochrane and multiple meta-analyses call for higher-quality RCTs and standardized outcome reporting.

These limitations may affect coverage decisions and documentation requirements.

Document adverse events and follow-up when considering device therapies.

Studies are small and carry risks including scarring and pigment changes.

Vitiligo: excimer and phototherapy: 308-nm excimer laser/lamps and NB-UVB/targeted phototherapy can produce repigmentation; combination regimens may improve repigmentation rates in small trials, but these therapies have not been shown to alter underlying disease trajectory and evidence is heterogeneous.

Evidence includes small RCTs and meta-analyses; careful consideration of goals and documentation is recommended.

Prior Authorization

Prior Authorization Expectations

Prior authorization is expected for several laser indications and clinical documentation should justify medical necessity based on condition-specific criteria, prior therapies, and outcome measures.

Prior authorization for laser epilation in pilonidal disease: Laser hair removal (LHR) is considered medically necessary for pilonidal sinus disease when used to control hair regrowth in patients who have had or are having surgery for disease management. Expect PA to include documentation of prior or concurrent standard care and planned surgical history.
Prior authorization: require prior standard therapy failure — For fractional ablative laser fenestration of hypertrophic burn scars, PA will likely require documentation that the individual has tried and failed at least one conventional treatment (e.g., hypoallergenic paper tape, pressure garments, silicone gel/sheeting) and that the scar causes functional impairment that the treatment is reasonably expected to improve.
Prior conventional therapy required for burn scars: Specifically document prior conservative therapies attempted and the functional impairment (e.g., limited range of motion) to support medical necessity for AFL-CO2 or similar procedures.
Prior medical therapy consideration for infantile hemangioma (IH): A specialist (hemangioma) consultation is recommended and documentation should note prior or concurrent use of beta-blocker therapy where applicable; laser may be considered for select IHs or residual changes after involution.
Conservative therapy trial may be expected: For many indications (e.g., acne, rosacea, PD), payers may expect trials of guideline-recommended conventional therapies and documentation of failure, intolerance, or contraindication before approving device-based treatments.
No explicit prior authorization statement provided for some device types: Where the policy text does not specify PA requirements for a given device, follow local payer PA rules and submit full supporting clinical evidence and rationale.

Denial Risk

Evidence and Denial Risk

Evidence quality varies by indication. Insufficient or very low-certainty evidence for many light and laser indications may influence PA decisions and could lead to denials without robust documentation.

Evidence insufficiency: Multiple systematic reviews and guideline statements describe very low- to low-certainty evidence for laser/light treatments in indications such as hypertrophic/keloid scars (Cochrane: very low-certainty), acne (AAD: insufficient evidence), rosacea/rhinophyma (limited/low-quality studies), and other dermatologic conditions.
Insufficient evidence may trigger denial: When evidence is judged insufficient to support effectiveness for a specific indication (policy lists several such indications as unproven and not medically necessary), expect potential denial unless strong case-specific documentation and rationale are provided.
NICE conditional recommendation may limit coverage: NICE recommends photodynamic therapy only for adults with moderate to severe acne if other treatments are ineffective/intolerant/contraindicated — this conditional stance may be used by payers to restrict coverage to refractory cases with documented prior treatment failure.

Documentation Required

Documentation to Include with Prior Authorization

Specialist consultation, validated outcome measures, and treatment course documentation strengthen PA submissions and support continued coverage decisions.

Specialist consultation & clinical documentation: For indications like infantile hemangioma, pilonidal disease, and complex scar management, include consultation notes from an appropriate specialist (e.g., hemangioma specialist, colorectal surgeon, burn/rehabilitation specialist) that explain rationale for laser therapy.
Outcome measurement documentation: Include validated scar and symptom scores where applicable (e.g., Vancouver Scar Scale [VSS], Patient and Observer Scar Assessment Scale [POSAS], scar thickness by ultrasound), Investigator Global Assessment (IGA), inflammatory lesion counts for acne trials, GAIS, erythema index, repigmentation percentages for vitiligo studies, and range-of-motion assessments for contractures.
Suggested outcome and safety documentation: For acne and similar trials note baseline and follow-up assessments (e.g., IGA and lesion counts at baseline, weeks 6 and 12); document adverse events and tolerability. For scar interventions include the number of treatment sessions, interval between sessions, and follow-up duration.
Studies report treatment sessions and follow-up intervals: Many AFL-CO2 scar studies used a median of ~2–3 treatments per patient with intervals of 1–3 months; pilonidal laser epilation trials used 4–5 sessions at 4–6 week intervals — include planned regimen and expected follow-up in PA requests.
Supporting documentation: Attach pertinent clinical evidence summaries, guidelines, FDA 510(k) device information (where available), and references cited in the policy to support the requested procedure.

Denial Risk

Coverage Limits and Cosmetic Determinations

Where policy or guideline language is silent or describes an intervention as cosmetic or not medically necessary, expect coverage denial unless compelling medical necessity and supporting evidence are provided.

No explicit authorization or coding/coverage for some devices: If the policy designates a therapy as unproven/not medically necessary (e.g., many forms of light and laser for onychomycosis, acne, rhinophyma, rosacea) or cosmetic (e.g., excimer for vitiligo per policy), PA is unlikely to be approved absent strong, case-specific justification.
Coding change — excimer laser: As excimer therapy is considered cosmetic/not medically necessary for vitiligo in this policy, claims using CPT 96999 for excimer may be denied as cosmetic; ensure documentation reflects an accepted medical indication if submitted.

Pilonidal sinus disease — definition and relevance to laser hair removal

DefinitionPilonidal sinus disease: chronic skin infection above the gluteal cleft that forms pits or sinuses frequently containing hair.

Pathophysiology relevanceThe disease is commonly attributed to hair follicle ingrowth in the cleft (acquired rather than congenital).

Relevance to laser hair removalLaser hair removal/epilation (LHR/LHD) can be effective as an adjunct or alternative to surgery to reduce hair in the natal cleft and lower recurrence risk.

Clinical implicationLaser epilation protocols in trials used diode (810 nm) or Nd:YAG (1064 nm) devices tailored to Fitzpatrick skin type.

PDL — Pulsed dye laser

DefinitionPulsed dye laser (PDL): a laser modality used to treat cutaneous vascular lesions; historically the most-studied laser for infantile hemangiomas and port-wine stains.

Clinical contextPDL has been evaluated in multiple RCTs and meta-analyses and is often reported as more effective than other laser types for superficial cutaneous vascular lesions.

Regulatory notePDLs are classified as Class II FDA devices; the first PDL was FDA-cleared in 1986 and various models have been subsequently cleared.

Laser epilation (LE/LHD) — definition and device types

DefinitionLaser epilation / Laser hair depilation (LE/LHD): use of laser devices (e.g., diode, Nd:YAG 1064 nm, alexandrite) to reduce or remove terminal hair.

Device typesCommon devices include diode lasers (e.g., 810 nm), Nd:YAG (1064 nm) for darker skin types, and alexandrite for lighter skin types.

Clinical applicationUsed to reduce hair in the natal cleft as adjunct to surgery for pilonidal disease and for cosmetic hair removal indications.

Trial parametersIn RCTs for pilonidal disease, treatments were given every 4–6 weeks for a series of sessions (e.g., five treatments).

Fractional CO2 laser — definition and use for scar remodeling

DefinitionFractional CO2 laser: an ablative fractional laser that creates microscopic zones of thermal injury to remodel scar tissue and improve texture, pliability, and thickness.

Use caseUsed for scar remodeling including hypertrophic burn scars with reported improvements in validated scar scales (VSS, POSAS) and scar thickness.

Evidence characteristicsSystematic reviews and meta-analyses report statistically significant improvements but note heterogeneity and generally low certainty of evidence.

AFL-CO2 — ablative fractional CO2 laser and typical treatment frequency

DescriptionAblative fractional CO2 (AFL-CO2) laser: an ablative fractional modality that creates micro-ablative columns to promote scar remodeling and functional improvement.

Typical treatment frequencyStudies commonly report a median of ~2.5 treatments per patient, with treatment intervals often ranging 1–3 months between sessions.

Indication specificsFrequently used for large, symptomatic hypertrophic scars unresponsive to conservative therapy, with outcomes measured by VSS and POSAS.

PDT — photosensitizer plus light components for acne vulgaris

ComponentsPhotodynamic therapy (PDT) combines a topical photosensitizer (e.g., 5-aminolevulinic acid [ALA] or methyl aminolevulinate [MAL]) with an activating light source (red, blue, IPL).

MechanismPhotosensitizer is applied and incubated to concentrate in lesions; activation by light produces reactive oxygen species that target local pathology (e.g., inflammatory lesions in acne).

Clinical evaluation in acneMultiple trials and systematic reviews show PDT (ALA or MAL + red/blue light or IPL) can reduce inflammatory lesion counts and serve as an adjunct when topical/systemic therapies fail or are not tolerated.

Photodynamic therapy (PDT) — alternate description

Alternate descriptionPhotodynamic therapy (PDT): treatment combining a photosensitizer (ALA or MAL) with an activating light source (red, blue, IPL, or other phototherapy) to target lesions.

Photosensitizers usedCommonly used agents include 5-aminolevulinic acid (ALA) and methyl aminolevulinate (MAL).

Clinical noteProtocols vary widely (photosensitizer concentration, incubation time, light source and dose, and number of sessions), leading to heterogeneity in trial results.

Nd:YAG 1064 nm laser — definition and study context

DefinitionNd:YAG 1064 nm laser: a near-infrared laser modality used for vascular and nonvascular dermatologic applications and studied for onychomycosis and hair removal.

Study contextIn pilonidal disease trials, Nd:YAG 1064 nm was used for Fitzpatrick skin types V–VI; in onychomycosis studies, 1064-nm Nd:YAG was one of the lasers evaluated in RCTs and meta-analyses.

Device noteParameters and efficacy vary across studies and indications; outcomes depend on wavelength, pulse, fluence and treatment protocol.

Excimer laser / Phototherapy devices — definition and FDA-cleared device context

DefinitionExcimer laser / phototherapy devices: targeted ultraviolet phototherapy devices (e.g., 308-nm excimer) and other phototherapy systems used for dermatologic disorders.

Regulatory contextSeveral excimer laser devices and hundreds of phototherapy devices have been FDA-cleared via 510(k) for dermatologic uses; product-specific information is available via FDA device listings.

Clinical usesUsed for localized phototherapy indications such as vitiligo and other disorders where targeted UVB/excimer exposure is applied; evidence and indications vary by device.

Pulsed Dye Laser (PDL) — FDA classification and device history

FDA classificationPulsed Dye Lasers (PDL) are classified as Class II devices by the FDA.

Device historyThe first PDL was manufactured and FDA-cleared (510k) by Candela Corporation in 1986; multiple subsequent models have been deemed substantially equivalent.

Clinical rolePDL is widely used and studied for cutaneous vascular lesions including port-wine stains and infantile hemangiomas, with meta-analyses reporting high resolution rates.

Excimer / Laser therapy — multiple device approvals/clearances for dermatologic uses

Regulatory overviewMultiple excimer, Nd:YAG, Er:YAG and other laser and phototherapy devices have received FDA approval/clearance (510k) for dermatologic uses; product-specific details are available through FDA device listings.

Device varietyDevices referenced include excimer lasers, NB-UVB lamps, PDLs, Nd:YAG, Er:YAG and various phototherapy/photothermolysis platforms.

Implication for practiceFDA clearance indicates substantial equivalence for intended device functions, but clinical indications and evidence base vary by device and condition.