Skin Disorders (Exam 2) Flashcards
Differentiation
Living cells lose nuclei and become flattened cornified cells
Pass through barrier zone
Barrier zone
Border zone between epidermal layers and horny later
Epidermal lipids released
How often does the epidermis renew?
Every 28 days
5 layers of the epidermis
Horny layer
Clear layer
Granular layer
Prickle-cell layer
Basal layer
Keratinocytes
Main epidermis cells
Lose nucleus and become corneocytes
Keratin
Strong, hydrophobic protein
Stratum corneum (horny layer)
Outer protective layer and major barrier to topical drug delivery
What type of drugs are administered through stratum corneum?
Small, lipophilic molecules that contain hydrophilic portion
Dermis
Hair follicles, sweat glands, nerves, blood vessels
Drugs reach dermis for systemic absorption
Topical Delivery
Administration to outer surface for LOCAL effect
Transdermal Delivery
Administration through skin for SYSTEMIC effect
Factors that alter systemic drug absorption (3)
Heat increases absorption
Children have higher surface area to mass —> greater exposure
Dermatological diseases
Acne vulgaris
Skin disorder of the pilosebaceous (hair follicle) units
Noninflammatory Lesions
Hair follicle (pore) becomes partially blocked
Closed Comedo
Whitehead
Open Comedo
Blackhead
Due to oxidation of melanin
Inflammatory Lesions
Hair follicle becomes blocked and inflamed
Can lead to scarring and hyperpigmentation
Papules
Solid, elevated lesion less than 0.5cm
Pustules
Vesicles filled with purulent fluid less than .5 cm
Nodules
Painful, firm lesions greater than 0.5cm
Cysts
Nodules that harden into larger, pus-filled lesions
Three main factors contributing to acne development?
Excessive sebum production
Hyperkeratinization
Bacterial growth
Excessive sebum production
Blockage of hair follicle
Androgens and cortisol increase sebum production
Hyperkeratinization
Excessive amounts of keratin contributes to cell blockage
Cells become stuck in hair follicle
Cutibacterium acnes
Gram positive bacteria that prefers anaerobic environments
How does C. acnes lead to acne?
Utilizes triglycerides in sebum as nutrients
Increased sebum production and follicle blockage leads to proliferation
Overgrowth attracts immune cells leading to pus and inflammation
Microcomedo
Microscopic plugging of corneocytes
May form weeks before visible lesion
Treatment for mild acne
Topical therapy
Lower risk of ADRs