Vitiligo and other disorders of hypopigmentation

Question 1

What is the average age of onset for vitiligo?

Answer 1

20 years old, women may have earlier onset

Question 2

What is the pathogenesis of vitiligo?

Answer 2

Genetic and non-genetic causes

The process of this destruction is somewhat unclear: hypotheses include autoimmune-mediated destruction, intrinsic defects in the melanocytes, cytotoxic metabolites, oxidative stress, or biochemical anomalies

Primary problem is the absence of functional melanocytes due to destruction of the melanocytes

Question 3

Clinical features of vitiligo?

Answer 3

Presents as a well-circumscribed, depigmented, asymptomatic patch or macule

Question 4

Differences between hypopigmentation and depigmentation on woods lamp?

Answer 4

Woods lamp can help show depigmentation vs hypopigmentation. Depigmentation almost glows with the woods lamp, think how teeth look under blacklight. Hypopigmentation is not as intense

Question 5

What are the most common sites of vitiligo?

Answer 5

Fingers, wrists, axillae, groin, genitals, and facial (around the mouth or eyes)

these areas can enlarge over time

Koebner phenomenon occurs

Question 6

What are the different clinical classifications of vitiligo?

Answer 6

localized (segmental can be a subset, usually in children); focal; or mucosal), generalized (most common), or universal (>80% of skin)

Question 7

What are the most common disease associations with vitiligo?

Answer 7

thyroid dysfunction (most common), DM1, Addison’s disease, pernicious anemia, halo nevi, alopecia areata, and uveitis

Question 8

What is Vogt-Koyanagi-Harada (VKH) syndrome?

Answer 8

Bilateral granulomatous uveitis, aseptic meningitis, dysacousia/deafness, poliosis/alopecia, and vitiligo

Question 9

What is Alezzandrini syndrome?

Answer 9

Unilateral facial vitiligo/poliosis with visual/hearing impairment on the same side

Question 10

What is Kabuki syndrome?

Answer 10

Developmental delay; congenital heart defects, skeletal anomalies/short stature, in addition to autoimmune issues (vitiligo)

Question 11

Treatment of vitiligo?

Answer 11

Topical steroids, TCI, topical vitamin D analogs, NB-UVB, phototherapy/excimer laser, systemic immunosuppressants, surgical therapies, and depigmentation

Question 12

What are some bad prognostic indicators for vitiligo?

Answer 12

Mucosal involvement, family history, koebnerization, and non-segmental disease

Question 13

Good prognostic indicators in vitiligo?

Answer 13

Recent onset, younger, and lesions of face/neck/trunk

Question 14

When pigment does return after treatment/as part of the disease course in vitiligo, where does the pigment come from?

Answer 14

Follicular regimentation is seen which represents the migration of melanocytes from hair follicles is the typical appearance

Question 15

Which form of vitiligo is more common?

Generalized or localized

Answer 15

Generalized

Question 16

What types of vitiligo is more associated with other autoimmune disease?

Answer 16

The generalized form

Question 17

Are halo nevi associated with vitiligo?

Answer 17

Yes

Question 18

What is one important histologyic difference between hypopigmented MF vs vitiligo?

Answer 18

The T-cells are more lichenoid in the MF, in the vitiligo they are more targeted to that area, just attaching the melanocytes

Question 19

What is the clinical apperence of a halo nevus?

Answer 19

Melanocytic nevus w/ surrounding well demarcated hypo-depigmentated skin

Question 20

What is the most common location for halo nevus?

Answer 20

Usually on the upper back

Question 21

What is the histology of a halo nevus?

Answer 21

Dense band of lymphocytes and macrophages surrounidng nests of melanocytes

Question 22

Prognosis of halo nevi?

Answer 22

Many regress over several months

Should do full skin-exam because can be a marker for melanoma

Question 23

What are chemical leukodermas?

Answer 23

Hypo or depigmentation of the skin or hair that results from chemical or pharacologic agents

Question 24

What are some chemicals/things that can cause chemical leukodermas?

Answer 24

Phenols: derivative monobenzyl ether of hydroquinone leads to depigmentation

Catechols and Sulfhydryls

topial steroids, hydroquinone, and imatinib can lead to hypopigmentation

Physical injuries from burns, freezing, radiation, lasers, surgery, UV and truama can damage melanocytes leading to hypo or depigmentation

Question 25

What is idiopathic guttate hypomelanosis?

Answer 25

Increased incidence w/ age and is more common in skin of color

• Thought to be from aging, sun exposure and genetics
• it presents as well-demarcated areas of hypo-depigmented macules that are more common on the extremitites

Question 26

In whom is progressive macular hypomelanosis most commonly seen in?

Answer 26

Darker skinned women from tropical regions

Question 27

What is the clinical presentation of progressive macular hypomelanosis?

Answer 27

Ill-defined, hypopigmented macules/patches on the trunk/upper extremities w/ no scale which can become confluent

Question 28

What are the treatments for progressive macular hypomelanosis?

Answer 28

Benzoyl peroxide, topical clindamycin, and UVA irradiation

There is believed to be a connection between C. acnes and this condition

Question 29

What is a nevus anemicus?

Answer 29

Pale, tyicpally unilateral area of skin (5-10cm) with irregular outline

• It is present from birth and typically found on the trunk

Question 30

What is a nevus anemicus caused from?

Answer 30

Decreased blood flow/vasoconstrition in the dermal papilla due to localzed hypersensitivity of blood vessels to catecholemines

• it is most noticible w/ heat or emotional stress that cases surrounding vasodiatlion

Question 31

What will be seen on diascopy for a nevus anemicus?

Answer 31

Causes blanching of surrounding skin, nevus no longer visable

Question 32

What are some differences between a nevus anemicus and a nevus depigmentosus?

Answer 32

Nevus depigmentosus: develops in infancy (as opposed to present at birth), has distinct midline demarcation and less distinct lateral borders, and on disascopy it does not disappear when pushed down upon

It is an actual decreases in melanosomes in melanocytes and keratinocyts

Question 33

What is the histopathology of nevus depigmentosus?

Answer 33

Normal number of melanocytes with decreased melanosomes in the melanocytes and keratinocytes

Question 34

What is segmental pigmentation disorder?

Answer 34

Is a variant of nevus depimentosus that can have a checkerboard pattern of hypopigmentation or hyperpigmentation

Question 35

What is hypomelanosis of Ito?

Answer 35

Hypopigmentation along Blaschko’s lines due to mosaicism (linear nevoid hypopigmentation)

Question 36

What is the most common location and time of onset for hypopigmentation of Ito?

Answer 36

Present at birth or early infancy/childhood

• Affects trunk and extremities more commonly can be unilateral or bilateral

Question 37

What is important to remember in regards to disease assocations with hypomelanosis of Ito?

Answer 37

30% of pts have CNS, MSK or ophthalmologic abnormalities

Question 38

What is the clinical progression/prognosis of segmental vitiligo?

Answer 38

Segmental vitiligo has a rapid onset but is often more stable. These pts don’t tend to progress to generalized vitiligo and the lesions may be responsive to therapies like topical calcineurin, steroids, or narrow-band UVB therapy