Skin Development Flashcards

1
Q

How do you get Piebaldism? What are the clinical features?

A
  • autosomal dominant, mutation in the KIT proto-oncogene
  • Impaired migration of melanocytes
  • clinical:
    • depigmented patches (congenital-present at birth) often with speckles within
    • stable, nonprogressive (remember vitiligo is progressive)
    • white forelock typical
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2
Q

How do you distinguish vitiligo from piebaldism?

A

History! Piebaldism is congenital and vitiligo is not

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3
Q

What causes Waardenburg Syndrome and what is associated with it?

A
  • rare disease, mutliple genes implicated in abnormal development of melanocytes
  • achromia (a white patch of hair or skin) with other features
    • deafness
    • heterochromia irides (eyes are 2 colors)
    • dystopia canthorum (wide distance between eyes)
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4
Q

What is port-wine stain?

A
  • malformed, ectactic, dilated capillary to venule sized blood vessels. usually called capillary malformation.
  • always present at birth, 0.3-0.6% of newborns
  • tend to darken and thicken over time
  • distributed along V1, V2, V3
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5
Q

How are port-wine stains distributed?

A

V1-ophthalmic branch, may extend to ocular conjuctiva

V2-maxillary branch

V3-mandibular branch, may extend o oral mucosa

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6
Q

What is Sturge Weber Syndrome? What are the symptoms?

A
  • most commonly associated port wine stains in the V1 dermatome (port wine stains in this region have other problems hence why its named)
  • Neurological
    • seizures
    • developmental delay
    • migraine headaches
    • tam track calcifications (calcification of the occipital and/or temporal cortex)
  • Ocular findings
    • congenital glaucoma
    • increase choroidal vascularity (tomato ketchup spot)
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7
Q

WHat is infantile hemangioma?

A

most common vascular tumor, 4-5%

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

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8
Q

Describe the Infantile Hemangioma growht cycle

A
  • at bith: white flat patch with fine pink-red vessels. pallor due to vasoconstriction
  • 1-2 wks: proliferation begins
  • growth pahse: variable, 3-9month
  • then slowly involutes
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9
Q

What is the difference between involution and resolution?

A

involution is when a scar forms bc its too big, otherwise it resolves

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10
Q

What is PHACE syndrome

A
  • P: Posterior fossa abnrmalities
  • H: hemangioma (segmental)
  • A: Arterial Anomalies
  • C: Cardiac Anomalies
  • E: Eye anomalies
  • S: Sternal clefting/ supraumbilical raphe
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11
Q

WHat is the significane of ectodermal dyspasia

A
  • over 150 rare syndromes have alterations in 2 or more structures that derive from the embryonic ectoderm
    • developmental defects in hair, teeth, nails, sweat glands, and the lends of the eye
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12
Q

What is the pathogenesis of Hypohidrotic ectodermal dysplasia?

A
  • most often X-linked recessive (most patients are males)
  • most common Ectodermal dysplasia
  • Ectodermal signaling pathway
    • ectodysplasin-A1 (EDA-A1)
    • EDA-A1 receptor (EDAR)
    • EDAR associated death domain (EDARADD)
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13
Q

What are the clinical features of HED?

A
  • square forehead with frontal bossing
  • flattened nasal bridge
  • low-lying ears
  • skin is thin and dry
  • sparse hair
  • hypo-anodonthia/peg teeth
  • decreased ability to sweat
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14
Q

WHat are the recommendations for HED?

A

avoid overheating

consult dentistry

recommend families ocntact National Foundation for Ectodermal Dysplasias

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15
Q

Epidermis and Epidermal derivatives originate from ___________

A

surface ectoderm

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16
Q

where are melanocytes derived from

A

neural crest

17
Q

where are Langerhans cells derived from?

A

bone marrow

18
Q

Where are Merkel cells derived from?

A

epidermal stem cells in the basal layer

19
Q

melanocytes, Langerhans and merkel cells enter and reside in what layer?

A

epidermis

20
Q

Where is the dermis derived from?

A

mesenchyme of regional origin

21
Q

During skin development what cross-signaling is essential?

A

during skin development, ectoderm-menchyme cross-signaling is essential

22
Q

What protects the skin from amniotic fluid?

A

the vernix caseosa protects the skin from amniotic fluid

23
Q

where are hair follicles, sweat glands and nails derived from?

A

eidermal buds that extend into the forming dermis

24
Q

what happens to the initial downy lanugo hair that is present at birth?

A

it is replaced near birth by course hair

25
Q

What are nails derived from?

A

epidermal thickenings at the tips of the digits

26
Q

What is Piebaldism due to?

A

an absence of melanocytes in affected skin and hair follicles

27
Q

what are the features of waardenburg syndrome?

A

white patches of hair or skin with deafness, heterochromia irides and dystopia canthorum

28
Q

Capillary malformations (port wine stains) in the V1 distribution can be associated with _________

A

seizures and glaucoma in sturge-weber syndrome

29
Q

Infantile hemangiomas are______ with a growth phase followed by ______

A

infantile hemangiomas are dynamic, with a growth phase followed by involution

30
Q

Patient with ________ have impaires ability to sweat and overheat

A
31
Q
A