Question | Answer |
Largest organ of the body | skin |
Is an organ and an organ SYSTEM | skin |
Three layers of skin | 1. Epidermis 2. Basal Layer 3. Dermis |
Epidermis | 1. derived from surface ectoderm 2. migrate from neural tube in circumferential bands |
Basal layer | -Second layer of skin -Rapidly dividing -Replaces surface cells as they slough off |
Dermis | - bottom layer of skin before subcutaneous tissue -derived from mesoderm |
Skin structures | 1. Melanoblasts/melanocysts 2. Hair follicles 3. Sebaceous glands 4. Mammary glands 5. Nipple/areola |
Melanoblasts/melanocysts | 1. Neural crest in origin 2. Located in basal layer |
Sebaceous glands | 1. Secrete sebum |
Sweat glands | 1. originate from surface ectoderm |
Mammary glands | 1. highly modified sweat glands 2. Mammary ridge- week 3 involuate by week 10-12 3. Supernumary nipple- on line of descent of ridge |
Skin pigmentation | 1. Eumelanin 2. Pheomelanin |
Eumelanin | brown, everyone has a lot |
Pheomelanin | Red color (as in red hair) multi-genetic |
Skin growth | 1. Passive growth (only grows in embryonic period and in response to other structures growing) |
Landmark and Measurements | 1. Texture 2. Pigmentation 3. Thickness 4. Mobility 5. Elasticity 6. Strength 7. Creases 8. Dermatoglyphs 9. Blaschko's lins |
Hyperelasticity | 1. Ehler's Danlos 2. Marfans 3. Other connective tissue DOs |
Skin is thickest on what part of the body? | The back |
Creases signify... | 1.Joint movement 2. in-utero movement |
Dermatoglyphs | -Fingerprints -Loops, whirls, Arches (high in DS) |
Blascko's lines | Mosaicism for skin problems |
Minor anomalies | 1. Nevi- Hamartomatous - Vascular - |
Mongolian spot | 1. Minor anomaly 2. Pigmented nevi 3. on lower back |
Cafe-au-lait spot | -Minor anomaly 1. Pigmented nevi 2. NF |
Freckles | -Minor anomaly 1. Pigmented nevi 2. NF |
Lentigines | -Minor anomaly 1. Pigmented nevi 2. 100s and 1000s 3. Darker 4. Lepard Synfrome, PTPN11 & RAF1 |
Coastal Maine | 1. Less typical of NF 2. More typical of McCume-Albright syndrome |
Hamartomas... what are they? | benign collections of mixed types of cells but in right area, but wrong specific place (ie. colon cancer syndromes) -Follow blaschko spots -Epidermal nevi are usually benign -Angiofibromas- small, red, raised, brown |
Epidermal nevi on the face signify | Brain malformation, seizures! |
Nevi on the face + groin | Fabry Syndrome (lysosomal storage DO) |
Nevi on the face | Tuberous sclerosis (hypopigmented ash leaf) |
Tumors under fingernails | Shagreen patches |
Vascular Nevi | -"Nevus flammeus" -"Stork bite" or "angel kiss" - 1/2 of all newborns |
Nevus flammeus/angel kiss/stork bite are very common in kids with | Beckwith Weidemann Syndrome |
Vascular nevi- port wine stain | -Dialated capillaries -Forehead |
Telangiectases | varicose veins |
Port wine stains are very common in what syndrome? | Sturge-Weber syndrome |
What is struge-weber syndrome? | -Port wine stains are common - Usually sporadic - Overgrowth of certain body parts |
Raised vascular nevi- two types | - Capillary -Cavernous hemangionomas |
Capillary hemangiomas | "Strawberry marks" Generally regress spontaneously |
Cavernous hemangiomas | -Darker, deeper down in dermis -Overgrowth? BWS -"Bag of worms: -Not too serious -Tends to regress |
Deformations of the skin | 1. Redundant neck skin (Noonan and Turner) 2. Redundant abd. skin (Prune belly) 3. Abnormal skin creases (simian crease) |
Dysplasias of the skin (structural changes in the dermis or epidermis) | 1. Cutis laxa 2. Hyperelasticity 3. Ichthyosis 4. Epidermolysis bullosum |
Dysplasias of the skin (pigmentary abnormalities) | 1. Hypopigmentation 2. Hyperpigmentation |
Cutis laxa | -Dysplasia/structural change in the dermis/epidermis - Menke's syndrome (X-linked and copper transport problems) |
Hyperelasticity | -Dysplasia/structural change in the dermis/epidermis - Ehler's Danlos |
Ichthyosis | -complete lack of elasticity to the skin -Harlaquin icthiocosis -Vulgarus (pretty common type) - X-linked you see a lot in prenatal (Low level of estriol) |
Epidermolysis bullosum | -Inadequate bond between dermis and epidermis -Fluid filled postules - Gene is right next to the ocular albinism genes (contiguous gene syndrome) |
Premature thelarche | -Dysplasia? - Premature breast development - abn. secretion of hormones - abn. response to normal hormones - Do endocrine work-up on pituitary tumors |
Absence of the sweat glands | - Dysplasia - Ectodermal dysplasia - Anhydrotic: males who can't sweat have ABNORMAL TEETH - Hypohydrotic: Females(X linked) don't sweat enough, have heat intolerance, abnormal teeth and hair, deep set eyes |
Malformations | - Cutis aplasia - Absence of the dermis w. intact epidermis (Focal dermal hypoplasia) -Skin tumors |
Cutis aplasia is often seen in... | Adams-Oliver syndrome (no dermis OR epidermis) |
Focal dermal hypoplasia is often seen in... | Goltz syndrome |
Types of skin tumors | 1. Neurofibromas 2. Lipomas 3. Xanthomas 4. Nevi 5. Shagreen patches |
Types of localized pigmentary abnormalities | 1. Hypopigmentation 2. Vitiligo 3. Piebaldism 4. Swirled hypo/hyper-pigmentation 5. Hyperpigmentation 6. Brown/black macules 7. Acanthosis nigricans 8. Poikiloderma |
NF Skim tumors | 1. Neurofibromas 2. Plexiform neurofibromas (diffused and deep in tissue, often involves nerves) |
Lipomas | Autosomal Dominant - Increase in frequency with age |
RAS Pathway and NF | neurofibromas appear in teenage years |
Xanthomas seen in | Hypercholesterolemia -Fatty tumors - True dominants are VERY SEVERE |
Giant hairy nevi is usually... | congenital |
Congential moles/nevi are usually... | isolated |
Characteristics of dysplastic nevi | 1. Asymmetry 2. Irregular borders 3. Change in color 4. Greater than 0.6 cm Higher risk of melanoma Pretty serious |
Characteristics of shagreen patches | 1. Thickened, bumpy skin patches 2. Peau d'orange -Tuberous sclerosis |
Hypopigmentation of the skin | -Ash-leaf spots -Tuberous sclerosis |
Piebaldism | -Isolated or familial - Waardenburg syndrome |
Vitiligo | - Usually autoimmune - Start loosing patches overtime |
Swirled hypopigmentation | -Hypomelanosis of Ito vs. Incontentia pigmenti - Don't cross midline - Single gene, X-linked - Often lethal in females - Better prognosis for males than females -Some are mosaic |
Blasckos Lines | 1. Incontentia pigmenti 2. CNS> MRDD 3. Teeth and hair problems 4. Four stages... 1)Blistered skin at birth (2) Thickened/raised skin (3) Flattened pigmentation (4) Linear hypopigmentation |
Hyperpigmentation of skin | - Multiple lentigines - Brown/black macules(mucous membranes) |
Brown/black macules of mucous membranes are typically seen in what syndrome? | Peutz-Jehgers (colon cancer, AD) |
Acanthosis nigricans are typically seen in what DO? | Pre-diabetes/ sign of glucose resistance (on nape of neck and nuchal axillary |
Poikiloderma | Mixture of hypo, hyper, and normal skin... PTEN Gene |
PTEN Gene sign | freckled end of penis |