Chapter 88: Skin Flashcards
anatomy of skin
Epidermis
Dermis
Subcutaneous tissue
topical medication preps
ointment
greatest absorption
good for dry skin, thicken skin, oozing skin
cream
mix of oil and water
not good for ozing skin
lotion
water or alcohol base
good for skin on skin areas
gel
water or alcohol base
liquefies on contact with skin
foam
aerated solutions
powder
talc or corn starch base
reduces friction between skin surfaces
paste
ointment plus powder
good for diaper rash
*more water, less absorption
Topical glucocorticoids
(cream, ointment, or gel)
Uses
To relieve inflammation and itching
Drying agent
Adverse effects
thinning of skin
Stretch marks
Purpura
Telangiectasia
Hypertrichosis
Possible systemic toxicity -More likely with higher doses and long-term therapy. Growth retardation in children, Adrenal suppression
Don’t want to se long term in one area- thin the skin. *
administration
Apply in a thin film and gently rub into the skin
Do not use occlusive bandages (or tight-fitting diapers and plastic pants) -Increases absorption
Keratolytic Agents
Promote shedding of horny layer of the skin
Primary agents and uses
Salicylic acid: Warts, corns
Sulfur: Acne, dandruff, psoriasis, seborrheic dermatitis
Benzoyl peroxide
treatment for thickening of ski
acne tx
Nondrug therapy
Cleansing
Drug therapy
Benzoyl peroxide
Antibiotics: Topical: Clindamycin, erythromycin. Oral: Tetracycline antibiotics,
PO isotretinoin, hormonal agents
Retinoids -toplical
Tretinoin
Adapalene
Tazarotene
azelaic acid
most common skin disease.
~85% of all teenagers get acne and it may persist into adulthood
acne AB
agents of choice: Doxycycline [Vibramycin], minocycline [Minocin]
Alternatives (resistance is common): Tetracycline [Sumycin], erythromycin [Ery-Tab]
See changes in 3-6m switch to topical for long term use
Isotretinoin
Used to treat severe nodulocystic acne vulgaris
Teratogenic -> ipledge
contraindicated in pregnancy
Triglyceride levels must be monitored
Potentiated by alcohol
Adverse effects
nose bleeds, lip inflammation, dry eyes, itching dry skin, muscle pain, stiffness, depression
tetracycline increases effects of isotretinoin
PO acne drugs
Hormonal agents
Spironolactone [Aldactone]
Sunscreens (UVA)
UVA penetrates the epidermis and deep into the dermis
UVA penetrates much deeper than UVB
UVA is the primary cause of immunosuppression, photosensitive drug reactions, and photoaging of the skin
most UV radiation is UVA
UVB
UVB penetrates into the epidermis but goes no deeper
Tanning and sunburn are caused primarily by UVB
Sunscreens (UVA and UVB)
Both UVA and UVB promote damage to DNA, so both can cause premalignant actinic keratoses, basal cell carcinoma, squamous cell carcinoma, and malignant and nonmalignant melanoma
sunscreens
Impede penetration of UV radiation to viable cells of the skin
Can protect against sunburn, photoaging of the skin, and photosensitivity reactions to certain drugs (e.g., tricyclic antidepressants, phenothiazines, sulfonamides, sulfonylureas)
Can also reduce the risk of actinic keratoses, squamous cell carcinoma, and melanoma
organic sunscreens
Also known as chemical screens
Absorb UV radiation and then dissipate it as heat
15 of approved sunscreens
Must include avobenzo
inorganic screens
Also known as physical screens
Scatter UV radiation
Titanium oxide and zinc oxide
Now micronized and clear for applying to skin
Good for nose, tips of ears, lips
Sun Protection Factor (SPF)
SPF is an index of protection against ultraviolet B (UVB) radiation
SPF does not address ultraviolet A (UVA) protection
Methods for obtaining SPF are not precise
Relationship between SPF and protection against sunburn is not linear (SPF 30 is not twice as much protection as SPF 15)