MelasmaMelasma

Biology of melanocyteBiology of melanocyte

Dendritic cell at basal layer of Dendritic cell at basal layer of epidermisepidermis

Produce melanin and send to Produce melanin and send to surrounding keratinocytesurrounding keratinocyte

Epidermal melanin unit Epidermal melanin unit (melanocyte:keratinocyte) = 1:36(melanocyte:keratinocyte) = 1:36

Biology of melaninBiology of melanin

Synthesis from melanosomeSynthesis from melanosome Transport to keratinocyte via Transport to keratinocyte via

dendritic process of melanocytedendritic process of melanocyte 2 type2 type

: eumelanin: eumelanin

: pheomelanin: pheomelanin

Melanin synthesisMelanin synthesis

BindingBinding

Melanocyte Melanocortin 1 Melanocyte Melanocortin 1

stimulating hormone receptorstimulating hormone receptor

adenylase cyclaseadenylase cyclase

Tyrosinase cAMPTyrosinase cAMP

Melanin synthesisMelanin synthesis

TyrosineTyrosine

tyrosinasetyrosinase

DopaDopa

Dopa quinoneDopa quinone

Eumelanin Eumelanin PheomelaninPheomelanin

Melanin synthesisMelanin synthesis

MSH MSH

MC1R mutation of MC1RMC1R mutation of MC1R

Eumelanin PheomelaninEumelanin Pheomelanin

Melanin transferMelanin transfer

PhagocytosisPhagocytosis

: melanin transfer to dermis: melanin transfer to dermis

: phagocytose by melanophage: phagocytose by melanophage EndocytosisEndocytosis

: melanin transfer to keratinocyte via: melanin transfer to keratinocyte via intercellular spaceintercellular space

MelasmaMelasma

Acquired bilateral symmetrical Acquired bilateral symmetrical hypermelonosishypermelonosis

Irregular light to gray brown macule Irregular light to gray brown macule and patchand patch

Ill defined marginIll defined margin Involved sun exposure areaInvolved sun exposure area Most common in women Most common in women

Distribution of melasmaDistribution of melasma

Central facial pattern (63%) : cheek, Central facial pattern (63%) : cheek, forehead, nose, chinforehead, nose, chin

Malar pattern (21%) : cheek, noseMalar pattern (21%) : cheek, nose Mandibular pattern (16%) :chinMandibular pattern (16%) :chin

Cause of melasmaCause of melasma

Light : UVA, UVB, visible lightLight : UVA, UVB, visible light Hormone : pregnancy, contraceptiveHormone : pregnancy, contraceptive pillpill Drug : dilantin, anti-malarial drug, Drug : dilantin, anti-malarial drug,

tetracycline, minocyclinetetracycline, minocycline Cosmetic :Cosmetic : perfume, colorperfume, color GeneticGenetic Malnutrition : liver dysfunction, B12 def.Malnutrition : liver dysfunction, B12 def.

Type of melasmaType of melasma

Epidermal melasmaEpidermal melasma Dermal melasmaDermal melasma Mixed epidermal dermal melasmaMixed epidermal dermal melasma

Epidermal melasmaEpidermal melasma

Light or dark brown colorLight or dark brown color Melanin deposition in basal, Melanin deposition in basal,

suprabasal layer of epidermissuprabasal layer of epidermis Larger melanocyte with more Larger melanocyte with more

noticeable dendritic process noticeable dendritic process

Dermal melasmaDermal melasma

Blue gray colorBlue gray color Perivascular melanophage at Perivascular melanophage at

superficial and middermissuperficial and middermis Melanin granule in dermisMelanin granule in dermis

Effective therapyEffective therapy

Retard melanocyte proliferationRetard melanocyte proliferation Inhibit melanosome formationInhibit melanosome formation Promote melanosome degradationPromote melanosome degradation

TreatmentTreatment

AvoidanceAvoidance SunscreenSunscreen Medication : hydroquinone, azelaic Medication : hydroquinone, azelaic

acid, retinoic acidacid, retinoic acid Chemical peelingChemical peeling DermabrasionDermabrasion Laser Laser

Laser treatment for Laser treatment for melasmamelasma

Target chromophore is melaninTarget chromophore is melanin Should destroy melanocyte in hair Should destroy melanocyte in hair

folliclefollicle Good in dermal and mix melasmaGood in dermal and mix melasma

Laser treatment for Laser treatment for melasmamelasma

Epidermal melanin removal : lPL, PDLEpidermal melanin removal : lPL, PDL Dermal melanin removal : Q-Dermal melanin removal : Q-

switched Ruby, Q-switched switched Ruby, Q-switched Alexandrite, Q-switched Nd:YAGAlexandrite, Q-switched Nd:YAG

FraxelFraxel

Epidermal melanin removalEpidermal melanin removal

No recovery timeNo recovery time Repigmentation after removalRepigmentation after removal

Dermal melanin removalDermal melanin removal

Minimal downtimeMinimal downtime Side effect : transient erythema, Side effect : transient erythema,

hypopigmentationhypopigmentation Repigmentation from melanin in Repigmentation from melanin in

melanophagemelanophage

FraxelFraxel

Epidermal and dermal ablationEpidermal and dermal ablation MEND formation and eliminated MEND formation and eliminated

through skinthrough skin Induce melanophage disruption and Induce melanophage disruption and

release melanin granule into dermisrelease melanin granule into dermis Downtime 3-7 dDowntime 3-7 d Long term improvementLong term improvement