Pathophys-Day 5 Ages I Flashcards
Ectoderm divides into __ and __
Extoderm and neuroectoderm (neural crest and neural tube)
Epidermis is formed from ?
ectoderm
5 layers of newly-formed epidermis
Strata basale, spinulosum, granulosum, lucidum, corneum
Lucidum is only on hands and disappears other places
Explain how epidermis changes during embryogenesis and later
Wk 6 - bilayered w periderm and basal layer
wk 8 - stratification begins - intermediate and basal layers
3rd trimester: terminally diff, filaggrin expressed
Week 8 defects during embryonic epidermal genesis lead to
ectodermal dysplasia
Ectodermal dysplasia presentation?
Hair, teeth, bone, skin deformities:
Clefting
Ectrodactyly
Sparse hair
Defects in epidermal genesis in the third trimester cause:
Ichthyoses
Ichthyoses presentation
Hyperlinear palms and soles; inherited, due to filaggrin mutation
Melanocytes originate in the _
neural crest
Where all do melanocytes migrate to?
Ear
Eye
Skin
Meninges
Describe the three categories of abnormal melanocyte development
Origin/migration/survival: patches of no pig
Melanin production: albinism
Melanosome formation/move: pigment dilution
What is piebaldism?
Patches of depigmentation (splotchy albinism!) from melanocyte mutation
Waardenberg syndrome?
Defective survival of melanocytes leads to patches of depigmentation
contrast to piebaldism>melano mutation
Presentation of Hermansky-Pudlak and Chediak-Higashi?
Silver hair from melanosome issues (remember - lysosome storage issues)
What are lines of Blaschko/Blaschkoid vesicles and when are they seen?
Migratory lines of melanocytes where mosaics have developed lighter skin
X-linked (lyonization)
Incontinentia pigmenti
XLD
Infants with IP are born with streaky, blistering areas. When the areas heal, they turn into rough bumps. Eventually, these bumps go away, but leave behind darkened skin, called hyperpigmentation. After several years, the skin returns to normal. In some adults, there may be areas of lighter colored skin (hypopigmentation).
Ocular, dental, CNS defects
Fatal in utero in males (only 1 X)
Where does dermis develop from
ectoderm and mesoderm
when is the dermal-epidermal junction fully functional?
12 wks
WHen is the skin’s barrier function fully developed?
3 wks post-partum
Important considerations to keep in mind for neonates and different dermal needs
- SA ratio much higher - fast topical absorb
- inc percutaneous absorp
- Increased transepi water loss
Considerations in the premature kid
Thinner stratum corneum
Longer than 3 wks for barrier fxn
Inc TEWL even comp to full-term
Inc infxn risk
What is vernix caseosa?
Protective membrane used in utero to keep baby’s skin dry made of epithelium, sebaceous secretions, and shed lanugo hair
What is cutis marmorata?
Reticulated skin appearance when baby is cold; goes away
What is lanugo?
hairy baby
Milia?
Little cysts in mouth, goes away
What is mongolian spot?
Benign flat, congenital grey birthmark with wavy borders and irregular shape
What is erythema toxicum neonatorum?
Benign, up to 50% babies
What are miliaria?
Occlusion of eccrine glands when baby is wrapped to tightly and too warm
What is seborrheic dermatitis?
Cradle cap
How can you tell if dermatitis diaperis is from candida?
Satellite lesions with redness
Gianotti-Crosti
rash in response to many different viruses, often EBV
HSP?
Strep in kids, vasculitis, glomerular nephritis is possible
Kawasaki disease
prob infectious
Big thing: puffy hands and feet, desquamation, strawberry tongue, potential coronary anyeurism
Atopic dermatitis pathogenesis
Type I HS
Filaggrin mutations assoc with AD
Barrier dysfunction leads to allergen exposure, immune dysregulation, and environmental interactions
Atopic dermatitis presentation
=eczema
Pruritis in past 12 months + 3 of:
- generally dry skin
- allergic rhinitis or asthma
- onset before 2
- hx of skin crease
- visible flexural dermatitis
Describe the infantile phase of AD
Cheeks, forehead, scalp, extensors
NOT DIAPER AREA
Itchy, ozzy, red
Childhood phase of AD
FLEXOR surfaces, wrist, ankle, neck
Lichenification
What are some features associated with childhood AD?
Denny-Morgan pleats: transverse eye lines
Allergic shiners: rubbing eyes
Allergic salute: rub nose w arm - crease
Hyperlinear palms
What are some complications of AD?
S aureus!
HSV
Molluscum contagiosum (poxvirus)
ADHD
Management of AD
Moisturization Bathing followed by immediate hydration and covering Avoid heat Calcineurin inhibitors Topical steroids
