Melasma

1
Melasma
2
Biology of melanocyte

• Dendritic cell at basal layer of epidermis
• Produce melanin and send to surrounding
  keratinocyte
• Epidermal melanin unit (melanocytekeratinocyte)
  136

3
Biology of melanin

• Synthesis from melanosome
• Transport to keratinocyte via dendritic process
  of melanocyte
• 2 type
• eumelanin
• pheomelanin

4
Melanin synthesis

• Binding
• Melanocyte Melanocortin
  1
• stimulating hormone receptor
• adenylase
  cyclase
• Tyrosinase cAMP

5
Melanin synthesis

• Tyrosine
• tyrosinase
• Dopa
• Dopa quinone
• Eumelanin
  Pheomelanin

6
Melanin synthesis

• MSH
• MC1R mutation of MC1R
• Eumelanin Pheomelanin

7
Melanin transfer

• Phagocytosis
• melanin transfer to dermis
• phagocytose by melanophage
• Endocytosis
• melanin transfer to keratinocyte via
  intercellular space

8
Melasma

• Acquired bilateral symmetrical hypermelonosis
• Irregular light to gray brown macule and patch
• Ill defined margin
• Involved sun exposure area
• Most common in women

9

• Melasma is a common acquired pigmentary disorder
  that occurs mainly in women (more than 90 of
  cases) of all racial and ethnic groups, but
  particularly affects those with Fitzpatrick skin
  types IVVI

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Distribution of melasma

• Central facial pattern (63) cheek, forehead,
  nose, chin
• Malar pattern (21) cheek, nose
• Mandibular pattern (16) chin

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Cause of melasma

• Light UVA, UVB, visible light
• Hormone pregnancy, contraceptive pill
• Drug dilantin, anti-malarial drug,
  tetracycline, minocycline
• Cosmetic perfume, color
• Genetic
• Malnutrition liver dysfunction, B12 def.

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Type of melasma

• Epidermal melasma
• Dermal melasma
• Mixed epidermal dermal melasma

13

• The use of a Woods lamp can often be very
  beneficial in determining the location of melanin
  deposition showing enhancement of color contrast
  in lesional skin for the epidermal type, but not
  the dermal types. The mixed type has enhancement
  in some areas of lesional skin, but not in other
  areas.2

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• Estrogen may play a role in melasma
  induction(OCP,HRT,pregnancy)
• Pregnancy induced melasma will recover after some
  months

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Epidermal melasma

• Light or dark brown color
• Melanin deposition in basal, suprabasal layer of
  epidermis
• Larger melanocyte with more noticeable dendritic
  process

16
Dermal melasma

• Blue gray color
• Perivascular melanophage at superficial and
  middermis
• Melanin granule in dermis

17

• Whether the melanin is deposited in the
  epidermis or dermis is important therapeutically
  because dermal hyperpigmentation is much more
  challenging to treat

18
Postinflammatory Hyperpigmentation (PIH)

• PIH represents a pathophysiologic response to
  cutaneous inflammation, such as acne, atopic
  dermatitis, lichen planus, and psoriasis. Similar
  to melasma, it is more obvious in patients with
  brown or black skin. It has no gender or age
  predominance.

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• The lesions are characteristically limited to the
  site of the preceding inflammation and have
  indistinct, feathered borders.7 Melanocytes can
  either be stimulated by the inflammatory process
  to become hypertrophic, thus secreting more
  melanin, or the number of melanocytes can
  increase

20

• . Epidermal hyperpigmentation (e.g., associated
  with acne) occurs when increased melanin is
  transferred to keratinocytes while dermal
  pigmentation (e.g., associated with lichen planus
  and cutaneous lupus erythematosus) occurs when
  the basement membrane is disrupted and melanin
  falls into the dermis and resides within
  melanophage

21

• Therapeutic goals for hyperpigmentation include
  promoting the degradation of melanosomes,
  inhibiting the formation of melanosomes, and
  retarding the proliferation of melanocytes.

22

• Because sun exposure is an important etiologic
  factor in hyperpigmentation, all patients should
  use daily, broad-spectrum, high SPF sunscreens
  and minimize sun exposure.

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Effective therapy

• Retard melanocyte proliferation
• Inhibit melanosome formation
• Promote melanosome degradation

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Treatment

• Avoidance
• Sunscreen
• Medication hydroquinone, azelaic acid, retinoic
  acid
• Chemical peeling
• Dermabrasion
• Laser

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Topical Treatments for Melasma

• In those patients with epidermal type melasma,
  there are multiple treatments available (see
  Table 2).6 Topical agents include phenols, e.g.,
  hydroquinone (HQ) retinoids, e.g., tretinoin
  azelaic acid kojic acid (KA) and glycolic acid
  (GA).

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hydroquinon

• 24 has been widely used for melasma therapy.
• inhibits the conversion of dopa to melanin by
  inhibitin theactivity of tyrosinase.
• may interfere with DNA and RNA synthesis, degrade
  melanosomes, and destroy melanocytes.

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• Reports of contact dermatitis in up to 25
• As an itchy eruption
• it is best to be tested in a hidden part before
  use
• Side-effects included irritant and allergic
  contact dermatitis, PIH, nail bleaching and
  rarely, ochronosis-like pigmentation.

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retinoids

• 0.05-0.1
• inhibiting tyrosinase transcription,interrupting
  melanin synthesis.
• While tretinoin may be effective in reducing
  melasma, it typically takes at least 24 weeks to
  see clinical improvement.

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azelaic acid

• 1)1520) a C9 dicarboxylic acid, is a
  reversible inhibitor of tyrosinase
• 2) shown to be as effective as HQ 4 but without
  its side effects.
• 3) The combination of azelaic acid with 0.05
  tretinoin or 1520 glycolic acid may produce
  earlier, more pronounced skin lightening. Adverse
  effects include pruritus, mild erythema, scaling,
  and burning.

30
KOJIC ACID

• KA 2 is generally equivalent to other therapies
  but may be more irritating.

31
Glycolic acid

• GA 510 is an alpha-hydroxy acid
• . It decreases pigment by many mechanisms
  including thinning the stratum corneum, enhancing
  epidermolysis, dispersing melanin in the basal
  layer of the epidermis, and increasing collagen
  synthesis in the dermis.

32

• , HQ 5, tretinoin 0.1, and dexamethasone 0.1,
  was first introduced in 1975 and termed the
  Kligman formula
• combination of HQ 4, tretinoin 0.05, and
  fluocinolone acetonide 0.01 (Tri-Luma,
  Galderma) proved better than any combination of
  two of the above agents, with 77 of patients
  showing complete or nearly complete clearing

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• Clinically significant improvement was noted as
  early as 4 weeks with maximum results at 8 weeks.
• The most common adverse effects were mild local
  irritation, erythema, and skin peeling
• GA peels to a topical regimen of HQ 2, GA 10
  and tretinoin 0.05 cream in PIH patients

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Laser treatment for melasma

• Target chromophore is melanin
• Should destroy melanocyte in hair follicle
• Good in dermal and mix melasma

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Laser treatment for melasma

• Epidermal melanin removal lPL, PDL
• Dermal melanin removal Q-switched Ruby,
  Q-switched Alexandrite, Q-switched NdYAG
• Fraxel

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Epidermal melanin removal

• No recovery time
• Repigmentation after removal

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Dermal melanin removal

• Minimal downtime
• Side effect transient erythema,
  hypopigmentation
• Repigmentation from melanin in melanophage

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Fraxel

• Epidermal and dermal ablation
• MEND formation and eliminated through skin
• Induce melanophage disruption and release melanin
  granule into dermis
• Downtime 3-7 d
• Long term improvement

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Chemical peeling

• With AHA like TCA,Salycilic acid,and