Melasma

Question 1

Clinical features?

Answer 1

Symmetrical patches
Brown- grey colour
Irregular borders
Location: central face, forehead, cheek, upper lip, nose
Worsens: Sun exposure

Question 2

Cause?

Answer 2

Hyper-functional melanocytes that is induced by:
Sun exposure
Genetics
Hormonal influence - oestrogen and progesterone

Question 3

Why does it happen? (Pathophysiology)

Answer 3

Sun exposure/UV radiation: UV upregulates/stimulate melanocyte activity (cells that produce pigment) = excessive pigment production

excessive sun exposure = tell your skin to produce more pigment = dark patches
hormones (pregnancy, pills) high oestrogen and progesterone linked to melsama: make melanocytes sensitive = excessive pigment
inflammation and heat = Triggers oxidative stress = pigment production and melasma flare

Question 4

Treatment Plan?

Answer 4

1st line - Protection
SPF 50+ and reduce sun exposure

Skincare
Antioxidant: Vitamin c
Tyrosinase: Niacinamide, kojic acid, azelaic acid,
retinol: increase cell turn over

2nd line - Combination therapies:
Chemical peels: Glycolic, inhibits tyrosinase, accelerate skin shedding
TCA peels 2-3 weeks weeks, 4-6 sessions)
Triple combination cream (TCC): hydroquinone, retinoid, corticosteroids

Third line - Laser/IPL
(DEEP PIGMENT) Q-switch/or Pico Nd:YAG for fits 4-6: break down pigment, minimal heat damage
(DERMAL PIGMENT) Q-switch Alexandrie 755nm) for fitz 1-3
Laser toning (nano)/Pico toning (1064nm): subcellular selective photothermolysis effect = reduce density of melanosomes in melasma lesion/reduce hyperactivity of melanocytes via targeting mature stage IV melanosomes within dendrites when they are being transferred to keratinocytes within Epidermal melanin unit
- target dermal melanophages: long wavelength and large spot size. use nano or pico

(SUPERFICIAL PIGMENT) 755nm (Alexandrite) and 694nm (ruby): superficial melasma
Non-ablative fractional laser (1550nm & 1927nm): improve collagen and reduce melasma vascularization

Oral (GP)
Tranexamic - inhibits plasmin-induces melanogenesis

Question 5

Is melasma epidermal, mixed epidermal-dermal or dermal pigment?

Answer 5

Mixed epidermal-dermal pigment