Introduction to basic principles & terminology Flashcards
Deep to superficial layers of epidermis
- stratum basale
- stratum spinosum
- stratum granulosum
- stratum lucidum
- stratum cornerman
Layer that is source of epidermal stem cells, cell division, melanocytes
Stratum basale
Central layer with desmosomal junctions link keratinocytes
Stratum spinosum
Layer containing keratinocytes and flaggrin within keratinocytes
Stratum granulosum
Paler layer that contains compact keratin
Stratum lucidum
Layer containing De Squamata green keratinocytes & flattened keratinised layer
Stratum corneum
Where is stratum lucidum found
Areas of thick skin
Layers of dermis, composition, contents & products of its fibroblasts
- 1-4mm
- mostly collagen
- blood vessels, lymphatics, mast cells, nerves, skin appendages
- collagen, elastin, glycosaminoglycans
Composition & function of subcutis
Fat: insulation, protection, energy
4 components of skin appendages
- hair
- nails
- sebaceous glands
- sweat glands (eccrine; apocrine)
Pilosabecous unit
Hair shaft, hair follicle, sebaceous unit, ar rector pili muscle
Summarise 4 phases of wound healing
Haemostasis: vasoconstriction, platelet aggregation, coagulation
Inflammation: vasodilation, phagocytosis
Proliferation-migration: granulation tissue formation, angiogenesis, re-epithelialisation
Remodelling: collagen, scarring
Lesion
Altered skin
Rash
Eruption
Pruritus
Itching
Macula
Small flat lesion
Patch
Large flat lesion
Papule
Small (<0.5cm) solid, raised lesion
Plaque
Large scaly raised lesion
Nodule
Large solid raised lesion
Vesicle
Small raised clear fluid-filled lesion
Bulla
Large raised clear fluid-filled lesion
Pustule
Small pus-filled lesion
Erosion
Superficial loss of some/all epidermis/mucosa only
Ulcer
Deep complete loss of epidermis and some dermis/submucosa
Scale
Flakes of desquamated stratum corneum, silvery appearance
Crust
Dried exudate
Excoriation
Epidermal loss
due to trauma
Lichenification
Thickening of skin from chronic rubbing
Fibrosis
Dermal scarring/thickening reactions
Fissure
Linear crack in skin, often v painful
Wheal
Short-lived (<24hrs) oedematous, well circumcised papule or plaque seen in urticaria
Telangiectasia
Dilated superficial dermal vessels
Atrophy
Thinning of epidermal and/or dermal tissue
Keloid
Hypertrophic scar - chronic overgrown original wound boundaries
Comedone
Dilated hair follicle full of sebum/keratin, open (black) or closed
Milium
Small superficial cyst containing keratin (usually <1-2mm in size)
Petechiae
Non-blanching small red/purple macules
Purpura
Large petechiae
Echymoses
Larger extravasating of blood - bruise-like patch
Onyholysis
Separation of nail plate from nail bed
Pitting
Punctuate depression of nail bed
Other than biopsy, name 5 dermatological tests
- simple excision
- skin scrapes/nail clippings/hair extraction
- skin swabs
- patch testing
- Doppler studies
Three means of skin biopsies
- curettage
- punch biopsy
- ellipse biopsy