Dermatology Flashcards
Regional Differences of Penetration: most penetrable to least
Mucous membrane Scrotum Eyelids Face Chest and back Upper arms and legs Lower arms and legs Dorsa of hands and feet Palmar and plantar skin Nails
Rule of 9’s
1 palm area = 1% BSA
2 palm areas at 2 times a day requires 30mg for 1 month
Fingertip Units (FTUs)
for corticosteroids
2 FTUs = 1g topical steroid
Corticosteroids: MOI
antimitotic effects on epidermis
Corticosteroids: absorption (normal skin, inc)
minimally absorbed on normal skin
inc absorption w/ occlusion
penetration inc in inflamed skin and exfoliative dz
inc absorption –> inc risk of systemic sx
Corticosteroids: Class I (potency, locations, duration, agents)
super high potency
scalp, palms, soles, extensor surfaces
<3wks
clobetasol proionate 0.05% cream, ointment
Corticosteroids: Class II (potency, locations, duration, agents)
medium-high potency
non-facial, non-intertriginous areas, flexural surfaces for limited periods
<6-8wks
betamethasone dipropionate 0.05% cream, ointment
fluocinonide 0.05% cream, gel, ointment, solution
Corticosteroids: Class III (potency, locations, duration, agents)
medium-high potency
non-facial, non-intertriginous areas, flexural surfaces for limited periods
<6-8wks
betamethasone dipropionate 0.05% cream, lotion
betamethasone valerate 0.1% ointment
triamcinolone acetonide 0.1% ointment
Corticosteroids: Class IV (potency, locations, duration, agents)
medium-high potency
non-facial, non-intertriginous areas, flexural surfaces for limited periods
<6-8wks
fluocinonide acetonide 0.025% ointment
triamcinolone acetonide 0.1% cream, ointment
Corticosteroids: Class V (potency, locations, duration, agents)
medium-high potency
non-facial, non-intertriginous areas, flexural surfaces for limited periods
<6-8wks
fluocinonide 0.025% cream
Corticosteroids: Class VI (potency, locations, duration, agents)
low potency
face, eyelids, genitals, intertriginous areas (thin skin)
1-2wks (>: skin atrophy, telangiectasia, steroid induced acne)
triamcinolone 0.1% cream
Corticosteroids: Class VII (potency, locations, duration, agents)
low potency
face, eyelids, genitals, intertriginous areas (thin skin)
1-2wks (>: skin atrophy, telangiectasia, steroid induced acne)
hydrocortisone 0.1% or 0.025% cream, lotion, ointment
Topical Glucocorticoid Therapy: ADEs
SYSTEMIC: HPA axis suppression cushing's syndrome psuedotumor cerebri growth retardation Na retention, edema
OCULAR: glaucoma cataracts retarded healing of corneal abrasion extension of herpetic infx inc susceptibility of bacterial/fungal infx
CUTANEOUS: (irreversible) atrophy striae distensae telangiectasias, purpura, ecchymosis hypopigmentation retarded wound healing contact allergic dermatitis (its the base) topical glucocorticoid habituation
Bacitracin: target organisms, base, ADEs
active against gram+’s (strep, staph, pneumococci)
ointment
poorly absorbed through skin
ADEs:
- allergic contact dermatitis (neomycin most likely)
- systemic toxicity (rare)
Mupirocin: target organisms, base, ADEs
active against gram+’s (incl MRSA)
cream, ointment
ADEs: stinging burning pruritis HA
Triple Antibiotic Ointment: agents, target organisms
POLYMYXIN B (gram-‘s: P aeruginosa, enterobacter, E coli)(all gram+’s are resistant)
NEOMYCIN (gram+’s and gram- bacilli: S aureus, E coli)(ADE:contact dermatoses)
BACITRACIN (gram+: staph, strep)
**GENTAMICIN has greater activity against P aeruginosa than neomycin
What is the best topical antibiotic per Mary Lou Brubaker?
Vaseline
What are the 4 factors involved in acne vulgaris pathogenesis?
- inc sebum production influenced by androgens
- keratin and sebum plug hair follicle –> hyperkeratosis w/ comedone formation
- Propionibacterium acnes bacteria (gram+) proliferates in sebaceous follicle (releases enzymes, pro inflammatory cytokines)
- inflammatory response
Which agents act on P acnes proliferation in acne vulgaris?
benzoyl peroxide
topical/oral abx
isotretinoin
Which agents act on abnormal keratinization of the follicle in acne vulgaris?
salicyclic acid
benzoyl peroxide
topical retinoids
isotretinoin
Which agents act on abnormal sebum in acne vulgaris?
antiandrogens isotretinoin topical/oral abx corticosteroids estrogens
Which agents act on inflammatory response in acne vulgaris?
oral/intralesional corticosteroids
topial/oral abx
Which agents are used to treat comedones?
topical tretinoin
Which agents are used to treat mild inflammatory acne?
topical retinoid OR benzoyl peroxide
+/- topical abx
Which agents are used to treat moderate acne?
topical retinoid AND benzoyl peroxide
+/- topical abx
-consider oral abx, derm referral, hormone therapy for F
Which agents are used to treat severe acne?
topical retinoid AND benzoyl peroxide
+/- topical abx
AND oral bx
-consider oral isotretinoin, derm referral, hormone therapy for F
Which agents are used to treat cystic acne?
intralesional triamcinolone
What is the preferred antibiotic for the treatment of acne vulgaris? (ADEs)
tetracyclines (doxycycline, minocycline > tetracycline)
**topial/oral abx NOT used as monotherapy bc resistance
ADEs:
- slate gray hyperpigmentation of skin
- drug induced lupus
- NOT used w/ pregnancy
- *minocycline: dizziness –> N/V
What topical antibiotics are used in the treatment of acne and what are their ADEs?
Erythromycin
ADEs:
-burning, drying, irritation (water based gel is less drying)
-gi upset
Clindamycin
ADE: C difficile
**both are combined w/ benzoyl peroxide to prevent resistance (benzaclin, duac, benzamycin)
Sarecycline: indications, drug family, ADEs
indication: inflammatory lesions of NONNODULAR mod-sev acne vulgaris
ages 9+
narrow spectrum tetracycline
ADEs: low rate similar to other TCNs
Retinoic Acid: def, action, ADE, directions for use
acid form of vitamin A
- action: dec cohesion bt epidermal cells and inc epidermal cell turnover
- expulsion of open comedones
- transformation of closed comedones to open
ADE: initially: slight erythema, mild peeling
NOT SPOT TX - apply to entire face
Tretinoin, Adapalene, Tazarotene: directions for use
applied every day at bedtime to dry skin only
avoid contact w/ corners of nose eyes mouth, mucous membranes
avoid sun exposure, use sunscreen
When do you see improvement with benzoyl peroxide in the treatment of acne?
about 5 days
Tretinoin, Adapalene, Tazarotene: expectations for the course of treatment
4-6wks: might appear worse initially
8-12wks: lesions clear
Tretinoin, Adapalene, Tazarotene: ADEs, patients who benefit
ADE: prolonged use –> inc collagen synthesis/thickening of epidermis
benefit for pts w/:
- photo-damaged skin
- thickened skin (psoriasis)
- atrophic areas
Tretinoin, Adapalene, Tazarotene: Retinoid Acid Receptor Selectivity
Tretinoin: beta, gamma
Adapalene: alpha, beta, gamma
Tazarotene: beta, gamma
Tretinoin, Adapalene, Tazarotene: Pregnancy Category
Tretinoin: C
Adapalene: C
TAZAROTENE: X
Benzoyl Peroxide: action
converted to benzoyl acid in epidermis/dermis
bacteriostatic against P acnes
peeling and comedolytic effects
will bleach clothing, bedding, towels
When are topical retinoids+antibiotics used as initial therapy?
when inflammatory lesions are present
When do you discontinue antibiotic use in combination therapy for acne?
when inflammatory lesions resolve
if not possible:
use benzoyl peroxide or benzoyl peroxide abx combo
What agents are used to maintain remission when antibiotic therapy is discontinued in combination therapy for acne?
topical retinoid
benzoyl peroxide/benzoyl peroxide washes PRN
