Lentigines/Solar Lentigo Flashcards
Clinical features?
Sun spot
Define border
Yellow-brown colour
Location face, hands arms etc.
doesn’t change in colour
can increase number
Cause?
Constant sun exposure (UVR damage) - accumulation with Aging
Why does it happen? (pathophysiology)
Protective mechanism/response: UV radiation activates/increase more pigment to produce to protect against DNA damage
Abnormal melanocyte activity:
UV induced: chronic UV exposure triggers genetic and epigenetic changes in keratinocytes = signals melanocytes in increase melanin production
UV exposure: Localised Melanocytic Hyperplasia (increase number of melanocyte): Lenitgos remain persistent due to melanin overproduction and structure changes in epidermis and dermis (epidermal ridges lengthenes = more basale layer for melanocytes to sit
Treatment Plan
Protect
Spf 50+, and avoid sun exposure
Topicals
Pigment inhibitors - kojic acid, vitamin c and azelaic acid
Retinol - increase cell turnover
Niacinamide - reduce melanin transfer to skin cells (inhibits darkening)
Laser and IPL
IPL - Target melanin
Q-switched Nd:YAG Laser (1064nm) (fitz 4-6) break down pigment in deeper lesions
Q-switched KTP (532nm) (fitz 1-3)
Laser toning (fitz 1-4): reduce hyperactivity of melanocytes via targeting mature stage IV melanosomes within dendrites when they are being transferred to keratinocytes within Epidermal melanin unit
fractional Laser (Fraxel) - Stimulate collagen remodelling and skin renewal
Combination therapies
Chemical peels - Glycolic acid - increase cell turnover and inhibits pigment
Is Lentigines epidermal or dermal pigment?
Epidermal pigment
