Derm Review!! Flashcards
How long does it take for a stem cell to go from stratum basal is to stratum corneum?
28 days, ~1 month
Desmosomes are located in the …?
Stratum spinosum, interlock keratinocytes
Hemidesmosomes do what?
Lock epidermis to dermis
Made of Type 17 collagen!
Dermal Layers
Top = Papillary dermis, interlocks with epidermal rete ridges Bottom = Reticular dermis, has thicker collagen bundles
Major constituents of the dermis
Collagen - TENSILE strength
Elastic fibers - resilience, SNAP BACK
Ground substance - facilitates diffusion
Disorder of elastin?
Acquired = Solar elastosis!! duh Congenital = PXE
Blistering disorder of DEJ?
Acquired = Bullous pemphigoid (Ab at hemidesmosome) COngenital = Junctional EB
Bullous (we said blistering). Remember congenital is EB (the kid in deem clinic)
Describe adnexal structures
Sebaceous gland for gliding the hair follicle through
Smooth muscle = erector pili
follicle in subcut fat
Hair cycle
Anagen = Grow, 3 yrs Catagen = Transition, 3 weeks Telogen = Resting, 3 months
THINK CELL CYCLE!! Ana = moves apart, Telo = chill in at either side. Cat is just weird, it’s in-between. But it’s transition, so its shortest
Anagen effluvium vs. Telogen effluvium
Loss of GROWING hairs (chemo)
Loss of RESTING hairs (postpartum, meds)
Acne vs RosaceaA
Acne: Hits oily areas, get comedones and blocked pores
Rosacea: FACE ONLY, erythematous disorder of central face, eyes in 1/4 pts, triggered by heat, cold, red wine, spicy foods, dilated vessels & flushing
Types of Dermatitis
Nummular = round, coin shaped
Atopic = “the itch that rashes,” flexural areas, dx in childhood
Seborrheic = dandruff, cradle cap
Intertrigo = Irritant Dermatitis in skin folds
Rash in flexoral area is a defect in…
Filaggrin, FILament, AGGregating protein in keratohyaline granules, important for barrier function of skin. As it breaks down, subcomponents are moisturizing factors for skin. These pts are more susceptible to atopic dermatitis and icthyosis
What does Psoriasis look like vs. Atopic Dermatitis?
Psoriasis: Thick, scaly, silver plaques on EXTENSOR surfaces
Atopic: thinner, scaly, exematous patches on FLEXORAL surfaces (and face)
What is Stasis Dermatitis?
Often seen with varicose vein and lower extremity edema, prior stasis ulcers
What is Seborrheic Dermatitis?
Cradle Cap:
- Flaky, white to yellowish oily scale on scalp
- Can become confluent with a thick scale covering most of the scalp
- Begins 1 week after birth and may persist for several months
Facial involvement is usually symmetric over the medial eyebrows, nasolabial folds and ears
Occurs in areas rich in sebaceous glands (scalp, face, ears, chest).
Characterized by flaky,
Types of HSR
I: IgE mediated, it binds Ag, cause degranulation of histamine from mast cells (hives, anaphylaxis)
II: IgG binds cell, lyses it via complement
III: IC Rxns, activate complement, inflamm cascade
IV: Allergic contact dermatitis, DELAYED HSR. Langerhans are APC and make memory T sensitized
Atopic dermatitis leans toward what type of T cell rxn?
Environment & genetics makes immune system lean one way or another
Th2: makes eosinophils and IgE. DIFFERENT than allergic rxn
Describe Impetigo
HONEY COLORED CRUST!!!
Tinea Versicolor
Subtle, discolored, slightly scaly patch
Due to malazecia purpura, heterosporum (yeast)
Scabies mite
–
Keloid
Common in ear if you’re prone
Erysipelas
Caused by STREP (treat w/ doxy)
Bright red, cliff-like drop off
Usually on face (also leg?)
Sunburn from what UV band?
Mostly UVB.
Erythema action from C to B
Solar from B to A
UVA from tanning bed
UV has what effects on skin?
Damage to DNA, RNA, lipids, protein Pro inflammatory Immunosuppressive Induction of innate defenses Induction of apoptosis Vit D synthesis
What are skin defenses to UVR?
DNA Repair machinery
Apoptosis of cells with DNA damage
Defenses against ROS
Melanin
Rough gritty papule on field of sun damage?
Actinic Keratosis
BCC has what defining feature?
Pearly rolled border, tumor of keratinocyte
Biggest risk factor for melanoma?
FAMMM syndrome
Sebaceous hyperplasia
From Sebocyte. More skin colored & yellow. Rolled border like BCC. Put into context w/ adjacent moles.
What does squamous cell carcinoma look like?
Ulcerated lesion with hard, raised edges, derived from keratinocyte
Kerato-acanthoma: raised, dry, defined borders, pinkish
Seborrheic Keratosis
Rough texture, stuck on, more brown, benign
What is a flat <1cm color change? Larger?
Macule
Patch if larger
What is a raiised, <1cm body?
Bigger?
More like plateau?
Papule = raised Nodule = bigger Plaque = plateau
Cell types for hyperplasia?
Vascular tissue- cherry angiomas, hemangiomas, port wine stains
Keratinocyte- basal/squamous cell carcinomas, actinic keratosis, seborrheic keratosis
Fibroblast- dermatafibroma
Sebaceous gland- nevus sebaceous, sebaceous hyperplasia
Common mutations leading to skin cancer and chemotherapeutic interventions
- BCC = patch1 mutation, vismodegib
* Melanoma = BRAF mutation, vemurafinib
