Chapter 16: Skin disorders Flashcards
purpose of topical corticosteroids
decrease inflammation, reduce itching, acute and chronic dermatitis
delivery types of topical corticosteroids
ointments, gels, aerosols, cream and lotions
low potency topical corticosteroids used for
eczema, iritant dermatitis, seborrhea, atopic dermatitis
high potency topical corticosteroids are used for
psoriasis, lichen planus, allergic contact dermatitis
are cream or ointments generally preferred
creams because they are nonocclusive and less greasy
when are aerosols preferred
weeping lesions or lesions on scalp
what is the drawback of lotions
often contain alcohol and sting
what is the advantage of gels
spread easily and can be used on scalp and hairy areas
most common adverse effect
of topical corticosteroids
cutaneous atrophy
(thinning of skin accompanied by telangiectasia)
other adverse effects of topical corticosteroids
striae, acne, hypopigmentation, alopecia, glaucoma,
adrenal suppression (may be life threatening)
conscientiou prescribing of topical steroids
drug absoprtion enhanced by increased skin temp, skin hydration, application to denuded areas
cannot be used extended periods in women who are or may become pregnant
what is the most commonly used topical corticosteroid
1% hydrocortisone
topical corticosteroid patient teaching
effects are short term, agents cannot be used frequently
symptoms may reappear after effects wear off
mechanism of action for topical corticosteroids
controls protein synthesis rate
depresses migration of polymorphonucleic leukocytes
reverses capillary permeability
reverses lysosomal stablization
prevents or controls inflammation
topical corticosteroid pharmacokinetics
absorption: no systemic absorption
distribution: 2/3 protein bound if systemically absorbed
metabolism: hepatic if absorbed
excretion: urine
half-life: 6.5 hours
clinical uses for topical corticosteroids
contraindication to topical corticosteroids
hypersensitivity
systemic fungal infection
dosage and application of topical corticosteroids
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topical corticosteroid patient education
avoid occlusive dressings
avoid with diapers (occlusive)
caution with pregnancy
etiologic agent of acne
propionibacterium acnes
mild acne
few to several papules and pustules but no nodules
moderate acne
several papules and pustules with a few nodule
severe acne
several papules, pustules, and nodules
drugs used to treat acne
keratolytics, antibiotics, vitamin A derivatives
names of mild keratolytics
benzoyl peroxide
salicylic acid
mild keratolytics mechanism of action
causes epidermis cells to shed faster to prevent pore clogging
how does benoyl peroxide decrease anaerobic bacteris in follicles
convert benzoic acid in skin and releases free-radical oxygen that oxidizes bacteria proteins
what can happen with high concentration formulations of benzoyl peroxide
hyperpigmentation and increased risk of skin irritation
antiobitc mechanism of action
decreases bacterial load and inflammation and infection that results from bacteria presence
Administration of antibiotics for acne
may be topical or oral
why are ABT and benzoyl peroxide often prescribed together for acne treatment
provides better results than either agent alone
side effects of ABT
light sensitivity, gastric upset, diarrhea
tetracyclines after expiration date
become more potent
don’t use
caution with ABT prescribing
children under 10
pregnant women
to avoid blue-gray discoloration of teeth
what infection may clindamycin lead to
c-diff
mechanism of action: vitamin A
retinoids prevent the formation of comedones by normalizing the desquamation of follicular epithelium
major side effects of retinoids
excessive drying, burning, skin inflammation
examples of retinoids
tretinoin (retin A), adapalene, tazoarotene
pregnancy category of retinoids
tretinoin - class C
tazarotene and isotrentinion - class X
Never use in pregnant women
treatment of urticaria
antihistamines
antihistamine mechanism of action
act on histamine receptor to decrease release of histamine from mast cells
first generation antihistamines
diphenhydramine
lead to drowsiness
second generation antihistamines
loratidine, fexofenadine, cetirizine
cause very little drowsiness if used at commonly prescribed doses
treatment of superficial bacterial infection
usually topical agents are sufficient
if not, oral agents are used
impetigo characterisitics
lesions with a honey colored crust
highly contagious
mupirocin
topical antibiotic that is effective against gram+ bacteria including MRSA
examples of oral agents utilized when topicals are insufficient
dicloxacillin, erythromycin, and amoxicillin with clavulanate
imidazole and triazole
antifungals that inhibit p450 system to stop conversion of lanosterol to ergosterol
(which is necessary for cell wall synthesis)
allylamines
antifungals inhibits epoxidase
(which is required for ergosterol)
griseofulvin
antifungal that binds to microtubules, stopping fungal mitosis
patient education on drugs treating superficial bacterial infections
wash with soap and water before applying
drugs used to treat superficial fungal infections
imidazole, triazoe, allylamines, griseofluvin
treatment of tinea cruris
topical treatment with any antifungal agentunless it has spread to lower thighs and buttocks, then use itraconazole or terbinafine
treatment of tinea capitis
oral griseofulvin usually used cause topical agents do not clear infection very well
treatment of tinea corporis
topically id 1-2 lesions present, otherwise orally. fluconazole once weekly x 4 weeks
treatment of tinea pedis
topical agent in most cases but highly kerototic lesion may require oral therapy
treatment of onchyomycosis and candiasis
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Topical conditions that are viral
shingles
chicken pox
herpes simplex
herpes zoster
antiviral agents mechanism of action
inhibits DNA synthesis to decrease viral replication
antiviral pharmacokinetics
metabolism: liver
excretion: urine
half-life: 8-10 hours
antiviral agents drug interactions
probenecid will increase drug levels
risk of toxicity when adinistered with theophylline
agents used for cleansing and disinfecting skin
NS, isopropyl alcohol, phenol derivatives, chlorhexidine, cationic surfactants, povidone-iodine, hydrogen peroxide
purpose of topical cleansing/disinfecting agents
decrease risk of infection by decreasing bacterial load
usually for intact skin
first degree burn
exhibit pain and erythema only
second degree burn
exhibits blisters and pain
third degree burns
full thickness that are insensate and usually require more than outpatient treatment
treatment of 2nd degree burns
silver sulfadiazine and covered with guaze. CHange twice daily
pressure ulcers
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topical drugs used for reatment of psoriasis
corticosteroids
vitamin D analogues
emollients
keratolytics
tazarotene
calcineurin inhibitors
page 303
oral drugs for treatment of psoriasis
cyclosporin A
methotrexate
acitretin
fumaric acid esters
page 303-304
IV/injectable meds for psoriasis
page 304-305
drugs to treat seborrhea
mild strength corticosteroids
shampoos containing selenium
mineral oil pretreatment for debridement
example of drugs used to treat seborrhea
page 305-306
mechanism of action for topical anethestics
blocks sodium channels, slowing conduction along nerves and disrupting the action potential
examples of topical anesthetics
lidocaine
benzocaine
prilocaine
application of topical anesthetics
only to intact skin
pregnancy, pediatric, geriatric implications
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