pigmentary disoders Flashcards
description of vitiligo
● An acquired depigmenting disorder, where there is complete loss
of pigment cells (melanocytes)
causes of vitiligo
● Thought to be an autoimmune disorder, where the innate
immune system causes destruction or loss of melanocytes, leading
to loss of pigment formation in the skin
presentation of vitiligo
● Presentation at any age
• A single patch or multiple patches of depigmentation (complete loss
of pigment), often symmetrical
● Common sites are exposed areas such as face, hands, feet, as well
as body folds and genitalia
● Favours sites of injury and this phenomenon is called the Koebner
phenomenon
description of melasma
● An acquired chronic skin disorder, where there is increased
pigmentation in the skin
causes of melasma
● Thought to be due to genetic predisposition, and triggered by
factors such as sun exposure, hormonal changes such as pregnancy
and contraceptive pills
presentation of melasma
● Brown macules (freckle-like spots) or larger patches with an
irregular border
● Symmetrical distribution
● Common sites are forehead, cutaneous upper lips and cheeks,
rarely can occur on neck, shoulders and upper arms
presentation of melasma
● Brown macules (freckle-like spots) or larger patches with an
irregular border
● Symmetrical distribution
● Common sites are forehead, cutaneous upper lips and cheeks,
rarely can occur on neck, shoulders and upper arms
Mx of melasam
● Lifelong sun protection
● Discontinuation of hormonal contraceptive pills
● Cosmetic camouflage
● Topical treatments that aim at inhibiting the formation of new
melanin such as hydroquinone, azelaic acid, kojic acid (a chelating
agent) and vitamin C
● Laser treatments need to be used with caution as the heat
generated by lasers can potentially cause post-inflammatory
hyperpigmentation.
ass conditions of vitligo
type 1 diabetes mellitus Addison's disease autoimmune thyroid disorders pernicious anaemia alopecia areata
