Pigmentary disorders Flashcards
What is vitiligo?
An acquired depigmenting disorder, where there is a complete loss of pigment cells (Melanocytes)
What is the cause of vitiligo?
Thought to be an auto-immune disorder, where the innate immune system causes destruction or loss of melanocytes leading to loss of pigment formation in the skin.
How does vitiligo present?
It presents as a single patch or multiple patches of depigmentation
It is often symmetrical
Common sites are exposed areas- face, hands, feet, body folds, genitalia
Often favours site of injury- koebner phenomenon
What is the management of vitiligo?
Minimise skin injury- cut, graze or sunburn can potentially trigger a new patch of vitiligo
Topical treatments- topical steroids and calcineurin inhibitors
Photopherapy- UVB therapy, excimer laser
Oral immunosuppressants- methotrexate, ciclosporin, mycophenolate mofetil
What is melasma?
This is an acquired chronic skin disorder, where there is increased skin pigmentation in the skin
What is the cause of melasma?
Genetic predisposition
Triggered by-
Sun exposure
Hormonal changes- pregnancy, contraceptive pills
The pigmentation is caused by an overproduction of pigment (melanin) by pigment cells (melanocytes)
What is the presentation of melasma?
Brown macules (freckle like spots) or larger patches with an irregular border
Symmetrical
Common sites- forehead, cutaneous upper lips and cheeks, rarely can occur on the neck, shoulders and upper arms
What is the management of melasma?
- Lifelong sun protection
- Discontinuation of hormonal contraceptive pills
- Cosmetic camouflage
- Topical treatments that aim at inhibiting the formation of new melanin- 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
