Moisturizers & Dry Skin Flashcards
Hemidesmosomes are located
between basal layer keratinocytes and basal lamina
Langerhans cells are located
Spinosum layer
Characteristics of keratinocytes in stratum basale
Stem cell niche
Desmosomes
K5 and K14 expressed
Characteristics of keratinocytes in stratum spinosum
Profilaggrin
Desmosomes
Keratin intermediate filaments
Characteristics of keratinocytes in stratum granulosum
Filaggrin (active)
Crosslinked keratin fibers
Lamellar bodies secrete lipid precursors
lipids in stratum corneum
Cholesterol ester
omega-hydroxyceramide
Sphingosine
Lipids in stratum basale and spinosum
- Cholesterol
- fatty acids
- triacylglycerides
- phospholipid
lipids in stratum granulosum
- cholesterol sulfate
- Ceramide, glucosylceramide, acylglucosylceramide
- Sphingomyelin
External factors causing dry skin
- Low relative humidity
- Wind currents–> evaporation
- Solvents/detergents stripping lipids
- Inflammation from UVR
Intrinsic factors causing dry skin
- Impaired SC function
- Reduced sebum production
- Dietary deficiency of essential fatty acids
Examples of impaired SC function
- Increased TEWL
- Abnormal keratinization/desquamation
- Reduced levels of NMF
Top 5 causes of dry skin
- Lifestyle
- Over-cleansing
- Sun exposure
- Extreme climactic conditions
- Aging
Vehicle types for moisturizers
- o/w emulsion
- w/o emulsion
- lamellar gel systems
Key ingredients of moisturizers
- Emollients
- Humectants
- Occlusive agents
Mechanism of emollients
- partial occlusion/lubrication
- affect skin FEEL
- “smoothing”
Mechanism of occlusive agents
forms a film on the surface of the skin to retard evaporation of water
Mechanism of humectants
binds water from the environment and retain water in equilibrium with the skin
Moisturizers that enhance skin barrier work by
mimicking the SC bilayer structure and assure long-lasting moisturization
Emollients provide _______, ________, and improve __________ while moisturizers provide _______ and improve ________
lubrication, skin smoothing, skin FEEL
water retention, barrier function
Categories of emollients
- silicones
- hydrocarbons
- esters
- ethers
- triglycerides
Occlusive moisturizers
- petrolatum
- dimethicone
- mineral oil
Humectant moisturizers
- Sodium lactate
- Glycols
- Sorbitol
- Sodium PCA
- Sodium hyaluronate
- polyglutamic acid
- hydrolyzed starch
Emollient moisturizers (specific)
- lanolin
- Capric caprylic triglyceride
Ester emollients
- Alkyl Benzoate
- Isopropyl Palmitate
- Octyl Palmitate