Pigmented Lesions Flashcards
vitiligo is destruction of melanocytes mediated by what?
the immune system
what is happening at the margin of vitiligo lesions?
lymphoproliferation
vitiligo is often associated with what other conditions?
autoimmune disorders
thyroid (hypo/hyper)
DM2
what is the most common depigmentation disorder of the skin?
vitiligo
1% of gen. pop.
what is the epidemiology of vitiligo?
male = female
children=adults
FH in 25-30%
what kind of lesion is present in vitiligo?
unpigmented macules (5-50mm) with sharply defined borders
what are the 4 types of vitiligo?
generalized
localized
segmental
acral/acrofacial
vitiligo often shows _________phenomenon
Koebner’s - lesions at sites of trauma or stress
how is the diagnosis of vitiligo typically made?
clinical presentation
may need Woods lamp esp. in lighter skinned individuals
the wavelength of a woods lamp is mostly ____ ________the visible spectrum of light
lower than
what’s the treatment fo vitiligo?
sun protection is the main treatment
cosmetic coverage
*topical steroids
*phototherapy - kill of proliferation
depigmentation (kill off remaining melanocytes)
surgical grafting - leaves scarring from graft
*active only
what kind of phototherapy is used for active vitiligo?
narrow band UVB (311-312 nm)
destroys immune cells attacking melanocytes
stimulates cytokine/gf release which stimulates melanocyte growth
what genes are defective in albinism?
the genes that produce melanin
What is the gene frequency for albinism?
1 in 70
but it is autosomal recessive
what are the two major dermatologic risks of albinism?
sunburn
skin cancer - particularly squamous cell carcinoma
what are solar lentigines?
liver spots
localized proliferation of melanocytes and melanization
what does the lesion of solar lentigines look like?
hyperpigmented, well-circumscribed lesions
what skin types are most at risk for solar lentigines?
Fitzpatrick Types 1-3
What two conditions must solar lentigines be distinguished from?
actinic keratosis
lentigo maligna
How do you distinguish solar lentigines from pre-malignant or malignant lesions?
warning signs:
rapid growth change
pain
itching
easy or recurrent bleeding
poor healing
what is the prevention for solar lentigines?
regular sunscreen use and limiting direct sun exposure
what is melasma?
progressive, macular, nonscaling, hypermelanosis of sun-exposed areas of face
what is acanthosis nigricans?
dark, hyperkeratotic streaks in skin folds
acanthosis nigricans is a common finding in what two types of patients?
diabetic
obese
what is post-inflammatory hyperpigmentation?
irregular, darkly pigmented macules and patches at sites of previous injury or inflammation (acne, psoriasis, trauma, lichen planus, etc.)
patients with which skin types are most susceptible to post-inflammatory hyperpigmentation?
Skin types IV-VI
how long do hyperpigmented lesions last?
months to years
what is the treatment of hyperpigmented lesions?
bleaching agents: hydroquinone 3% or azelic acid 20%
not great, hard to control
