Skin development

Question 1

Precursors of skin

Answer 1

Head: neural crest, head mesoderm

Trunk and limbs: somatic mesoderm

Back: dermatome

Question 2

Beginnings of epidermis development

week 3
Week 4-8
Week 11-12
month4-6

Answer 2

week 3- ectoderm, mesenchyme

Week 4-8- peridermal cell, ectoderm, mesenchyme

Week 11-12- peridermal, intermediate layer, basal layer

month4-6- cornified layer

Question 3

piebaldism

Answer 3

autosomal dominant

Mutation of the KIT proto-oncogene

impaired migration of melanocytes

Clinical- depigmented patches (congenital) often with speckles within

Stable, nonprogressive

White forelock typical

Question 4

Waardenburg

Answer 4

Rare disease

Multiple genes implicated, result in abnormal development of melanocytes

Achromia: white patches of skin and hair with other features (deafness, heterochromia irides, dystopia canthorum)

Question 5

port wine stain

Answer 5

malformed, ectatic, dilated capillary to venule sized blood vessels

always present at birth

Occur in about .3%-.6% of newborns

Tend to darker and thicken over time

on face follow V1, V2 and V 3 with V1 worst

Question 6

Sturge Weber syndrome

Answer 6

Most commonly associated with V1 dermatome port wine stain

Neurologic: seizures, developmental delay, migrain headaches, tram track calcifications in occipital or temporal cortex

other: congenital glaucoma, increased chordial vascularity

Question 7

Infantile Hemangioma

Answer 7

infantile hemangioma is the MOST COMMON VASCULAR TUMOR (with an incidence estimated between 4-5%

composed of proliferating endothelial like cells that become clinically visible within the first months of life

At birth, white flat patch with fine vessels, 2 weeks to 9 months growth , vasoconstriction, they slowly involute

Question 8

PHACE syndrome

Answer 8

P-posterior fossa abnormalities

H- hemangioma (segmental)

A- arterial anomalies

C- cardiac anomalies

E- eye anomalies

S- sternal clefting/supraumbilical raphe

Question 9

ectodermal dysplasia

Answer 9

over 150 rate syndrome alterations in 2 or more of the structures that derive from the embryonic ectoderm:
developmental defects in hair, teeth, nails, sweat glands, and lens of the eye

Question 10

Hypohidrotric Ectordermal dysplasia (HED)

Answer 10

X linked recessive

most common ectodermal dysplasia)

Ectodysplasin signaling pathway: Ectodysplasin A1 (EDA-A1), Eda-A1 receptor (EDAR), EDAR associated death domain (EDARADD)

square forehead with frontal bossing, flattened nasal bridge, low lying ears, skin is thin and dry, sparse hair, hypoanodontia/peg teeth, decreased ability to sweat

Treatment: avoid overheating, consult dentistry