Robbins concepts Flashcards
6 requirements for describing skin lesions?
Quantity # Size Color Shape Palpability (shadow) Texture Location
Small flat any shaped lesion?
Macules
Lesion confined to epidermis, no fluid, not raised?
macule
Flat lesion >5mm (1cm)?
Patch
> 1cm raised lesion?
Plaque
raised lesion <1cm?
Papule (pimple)
Large, deep raised lesion >1cm? Grows into dermis
Nodule
Small raised fluid filled lesions?
Vesicles
Larger >1cm blister or fluid filled lesions?
Bulla
vesicle filled w/ pus?
postule
superficial loss of epidermis>
Erosion
Erosion involving the Dermis?
Ulcer
Four layers of the skin
Sup--> Deep Stratum Corneum stratum granulosum stratum spinulosum stratum basale
Protein found within granular cell layer which retains water in keratinocytes?
Filaggrin
Autoimmune blistering disease against Ag @ basal cell layer?
Bullus pemphigoid
Causes accelerated rate of epidermal turnover?
psoriasis
Three main cell types in the epidermis?
Keratinocytes
Melacocytes
Langerhan cell
Benign collection of melanocytes?
Nevi (MOLE)
Excessive collagen deposition in response to injury?
Keloids
Use for smooth, non hairy, dry thick lesions?
Ointment
Use of acute exudative inflammation intertriginous areas?
Cream
For hairy areas?
Lotion
Six components of topical prescription?
Generic name vehicle concentration Directions amount refills
Loss of intercellular adhesion of keratinocytes?
Acantholysis
Diffuse epidermal hyperplasia
Acanthosis
Consequence of contact w/ poison ivy?
Contact dermatitis (CD4+ T cells) Delayed type hypersensitivity (T4)
Pt w/ wide diversity of lesions including macules, papules, and bullae + characteristic Targetoid Lesions consisting of red macules w/ pale vesicular/ eroded center?
Erythema Multiform
Caused by Hypersensitivity to Drugs or Infections
ABCDEs of mole or melanoma?
Asymmetry Boarder irregularity Color Diameter> 6mm Evolution
Most common melanoma site in MEN? Women?
Back (M)
Legs + back (W)
Immune regulation of the skin is done by?
Langerhan cells-> Epidermis
Lymphocytes and Dendritic cells-> Dermis
Thermoregulation in skin?
Microvasculature in the Dermis
Bullous Pemphogoid is caused by?
Auto antibodies against hemidesmosomes
Disease caused by Anti-desmosome Abs
(type II HS)?
Pemphigus vulgaris
Disease caused by mutation in Nucleotide excision repair mechanism?
Xeroderma pigmentosum
Hypohidrotic ectodermal dysplasia?
EDAR gene mutation leading to abnormal hair follicles + sweat glands + and Teeth
** Unable to thermoregulate
Job of Melanin?
Protect the skin from UV light
Cells making up the epidermis?
Keratinocytes
Langerhan cells
Melanocytes
Merkel cells
What is in the Dermis layer?
Fibroblast –> collagen
Elastic fibers
Blood vessels
Nerve Endings
Epidermis cell layers renew every____ and cells have a _______ rate of apoptosis?
28+ days
LOW
Basal cells adhere to the basement membrane w/?
hemidesmosomes
Cells in the spinous layer are held together using?
Desmosomes
At what layer to epidermal cells STOP dividing and begin differentiating?
Stratum Spinosum
What do the cells in the Spinous layer develop to help with Barrier function?
Lipid granules–> Lamellar granules
Granular layer cells synthesize what?
Profillagrin inside Keratohyaline granules
What is secreted into the intercellular layer to form a water tight seal?
Lipids in Lamellar granules
Which cells process Profillagrin into fillagrin?
Keratinocytes @ the Stratum coneum layer
Function of Fillagrin?
Keeps water in the cells
These two substances join to form macrofibrils for a protective layer?
Fillagrin + Keratin
What makes up intermediate filaments and is the major structural protein of Keratinocytes?
Keratin
Contains large amounts of Sulfur-containing acid cysteine?
Keratin
Dendritic cells in mid-epidermis responsible to allergic rxns and tumor surveillance?
Langerhan cells
Merkel cells?
Light touch receptor cells in the Basal layer of epidermis
What is the primary cell in the Dermis?
Fibroblasts–> synthesize and degrade collagen + elastin + glycosaminoglycans
Where in the skin are mast cells located?
Dermis
Atopic Dermatitis is associated w/ mutation of what protein?
Fillagrin
Epidermolysis Bullousa simplex is associated w/ what mutation?
Mutations in Keratin 5/14
** Blisters occur at sites of high stress
Psoriasis is associated w/ conditions and WHY?
increases Risk for Heart attacks & Strokes because its a Chronic inflammatory state
**also associated w/ Arthritis
Condition is caused by genetic (HLA polymorphisms) and environmental factors causing release of Cytokines which causes Keratinocyte hyperproliferation?
Psoriasis
Auspitz sing for Psoriasis?
Removing of scales causes multiple small bleeding points
“Pruritic, Purple, Polygonal, Planar Papules and Plaques?”
Lichen Planus (6 Ps)
Results from CD8+ mediated cytotoxic response against Basal cell layer and the Dermoepidermal junction?
Lichen Planus
**Often cuased by viral infections or Drug exposure
Wickham striae?
White dots or lines funning though flat-topped purple polyglonal papule in LICHEN planus
“Sawtoothing” inflammation of the desmoepidermal junction?
Lichen planus
Symmetrical well developed epidermal hyperplasia + hypergranulosis and Hyperkeratosis located in extremities + elbows + glans penis + and oral mucosa?
Lichen Planus
Tetrad of Cough, Coryza, Conjunctivitis, and Koplik spots?
Diagnostic of Measles (Rubeola)
Tiny white or blue-gray lesions in buccal mucosa that precedes with maculopapular rash?
Koplik spots
Febrile maculopapular rash that begins in the face and spreads to the trunk and extremities + postauricular LAD?
Rubella (Togavirus)
Low fever, LAD, and Red-purple papular skin lesions in immunocomprimised patient with scratch marks?
Bacillary angiomatosis (Cat scratch fever)
Organism most responsible for skin and soft tissue infections such as Folliculitis and abscesses?
S. aureus
Superficial skin infections?
Impetigo
deeper dermal abscesses most commonly caused by?
S. aureus
Less commonly: Strep pyogenes
Lesion characterized by accumulation of PMNs beneath stratum corneum producing a postal?
Impetigo
PAS and Gomori methanamine silver stain are helpful in identifying?
Fungal organisms
Verrucae are commonly caused by?
Warts caused by HPV
immunoflourescence shows uniform deposition of IgG Abs along cell membranes of keratinocytes in a “FISHNET” pattern?
Pemphigus vulgaris
Acantholysis?
Lysis of intercellular adhesion junctions btwn neighboring squamous epithelial cells in Pemphigus
Suprabasal acantholytic blisters?
Pemphigus vulgaris
Pg: Linear deposition of igG antibodies and complement in the epidermal basement membrane?
Bullous pemphigoid
Gross appearing differences btwn blisters of Pemphigus vulgaris and bullous pemphigoid?
Non-roofed blisters= Vulgaris
Roofed= Pemphigoid
Pg: granular IgA deposition and on selectively localized tips of dermal papillae. Associated w/ cross reactivity of IgA to epidermal transflutaminases?
Dermatitis Herpetiformis
Dermatitis Herpetifromis is associated w/ what dz? Treatment?
Celiac disease
** responds to Gluten free diet
UVR that penetrates ozone layer?
> 300nm (UVB + UVA)
UVB characteristics?
290-320nm
Filtered by glass window
Causes Sunburn
Minor cause of Photoaging
UVA characteristics?
320-400nm Least potent Penetrates glass Penetrates Deep into skin Major cause of PHOTOaging
Factors that modify UVR?
Altitude
Surface reflection (Snow= highest)
Could cover-> only scattered
what is a chromophore?
Molecule that absorbs UV
Major Chromophore in Skin?
DNA
*aromatic AA
Acute effects of UVR on skin?
Sunburn (acute inflammation) Immunomodulation Epidermal hyperplasia Vit D photosynthèses DNA damage
What causes sunburn?
UVB
*SPF is determined by testing erythema caused by UVB
Immediate Suntan?
UVA–> redistribute or oxidize existing melanin
Not protective
short lasting (hours)
Delayed suntan?
UVB–> increased melanin production
Photoprotective
Long lasting
UVR damage on DNA?
Direct–> absorption by bases
Indirect–> other chromophores absorb
Specific damage to DNA by UVR?
Pyrimidine Dimers
Cyclobutane dimers
6,4 photoproducts
UV signature mutations?
C-> T
CC–> TT
Defense mechanism against UVR?
Corneum–> reflection
Melanin–> absorption
DNA repair–> NER system
Apoptosis
heritable disease characterized by sensitivity to UV and early onset of skin cancers?
Xeroderma pigmentosum
PG of Xeroderma pigmentosum?
Defective NER system
Effects of XP defect?
Skin cancer
Eyes: cataracts + tumors + degeneration
CNS degeneration
What cells disappear from the skin following UV exposure?
Langerhan cells–> immunosuppression in the skin