Final Exam Derm Agents Flashcards
Keratinocytes
Cells that make up the basal layer of the epidermis (95%)
As new keratinocytes are made old keratinocytes migrate up the epidermis (differentiation) or stay in the basal layer (basal cells)
Once tin the stratum corneum they become squamous cells that no longer multiply
-Dead skin cells-> tough / dry outer layer of skin
Drug absorption through the skin
Drug applied directly to the skin
Drug passively diffuses across the stratum corneum
Absorption through the capillaries in the dermis
Drug can enter systemic circulation
-Transdermal vs topical
Factors that affect drug absorption
Hydration – More moisture, more absorption
Damage to stratum corneum – More damage, more absorption
Temperature / Friction – Increased temperature/friction, increased absorption
Drug particle size – Smaller, soluble drugs absorb better
Drug delivery systems
Selection of delivery system
Common skin diseases treated with topical products
Acne – Pathophys
Increased Sebum production – Caused by increase in androgen levels
Hyper-keratinization – causes clogging of the follicle
Colonization of P. acnes – Gram + anaerobe colonizes and proliferates
Release of inflammatory mediators – Papules, pustules, etc
Clinical Presentation of Acne
Topical treatments for acne
Topical Retinoids – MoA
MOA: Stimulate epidermal cell turnover and decrease cell cohesiveness
Unplug follicles
Reduce inflammation
Tretinoin
Naturally occurring form of vitamin A
Adapalene (now available OTC)
Greater anti-inflammatory effects vs. tretinoin?
Tazarotene
Effective, but poorly tolerated
Topical Retinoids – ADEs
ADEs:
Skin irritation, peeling, dryness
Erythema
Hyperpigmentation (tretinoin > adapalene)
Acne may worsen with initial use
May take up to 3 months for full effect
Wear sunscreen
Avoid ultraviolet lights
Apply at bedtime
Available in cream and gel
Benzoyl peroxide (BPO)
MOA: Antimicrobial, anti-inflammatory, Keratolytic effects
May inactivate some formulations of tretinoin, so avoid use or separate times of administration
Ok to use with adapalene or tazarotene
No reported resistance
Often used in combo with other therapies
Efficacy is not concentration dependent
ADEs: Contact dermatitis, erythema, skin dryness, peeling, bleaching
Misc. Topical Treatments for Acne
Atopic Dermatitis – PathoPhys
Emollients
Cornerstone of management for atopic dermatitis
Made up of a fat-like substance that soften and soothe skin, retain moisture and provide protective barrier
Lanolin
Mineral Oil
Shea Butter
Cocoa Butter
Used in combination with topical steroids
Steroid sparring
Apply emollient first, wait 5-15 minutes, then apply steroid (or other treatments)
Topical Steroids – MOA
MOA: Decrease inflammation, modulate immune response and vasoconstrict blood vessels to minimize redness, warmth and swelling
Used for acute flares
Categorized by and differ by potency
Seven groups
Potency determined by vasoconstricter assay
-Also determined by vehicle/formulation
No single agent proven better than another
Once or twice daily admin preferred
Steroid agent and potency
How to choose Topical steroid
Topical steroid ADEs
Skin atrophy
Striae
Rosacea
Superficial infections
Hypopigmentation
Darker skin tones
Contact dermatitis
Tolerance
Tachyphylaxis
Systemic side effects
Adrenal suppression
HTN
Hyperglycemia
Application
Crisaborole
MOA: Not fully known; Non-steroidal inhibitor of PDE-4
Ointment
Studied in children and adults > 2 years of age
Mild to moderate atopic dermatitis
ADEs:
Common: application related pain (burning stinging)
Rare: hives, itching, swelling
Psoriasis PathoPhy
Treating mild to moderate Psoriasis
Calcipotriene
Synthetic Vit D3 analog
MOA: Inhibits epidermal keratinocyte hyperproliferation
Can be combined with other treatments including steroids
Steroid sparring effect
Can help improve UVB light therapy
Apply AFTER light therapy not before
ADEs: Cutaneous irritation, burning, stinging, hypercalcemia (rare-> large areas only)
Sun protection
Ultra-violet (UV) rays emitted from the sun and indoor tanning systems
UVA -> most abundant rays to reach earth’s surface; penetrate into deep layers of the skin
-Causes aging, wrinkling, increase risk of cancer
UVB-> absorbed into superficial layers of the skin; partial absorption from ozone layer
-Causes reddening sunburn, increase risk of cancer
UVC-> absorbed by ozone layer and do not reach earth’s surface
Sunscreen
Should protect against UVA and UVB rays
Sun Protective Factor (SPF) of at least 15 is recommened for protection
SPF 15 protects against 93% of the sun’s UVB rays
-It will take skin 15 times longer to redden with the use of sunscreen compared with no sunscreen
SPF 30 pretects against 97%
SPF 45 protects against 98%
Apply 1 ounce (2 Tbsp) 30 minutes before sun exposure
Reapply every 2 hours or after swimming or sweating
Active ingredients in sunscreen
Important definitions/claims
