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
Isotretinoin: indications, contraindication
indications: sev cystic acne, hidradenitis suppurativa
contraindication: TERATOGENIC
Isotretinoin: ADEs
dry mucous membranes, xerosis, cheilitis, conjunctivitis, epistaxis, pruritus
joint pain
thinning hair
HA
nausea
mood swings, suicidal ideation, sleep disturbances
hypertriglyceridemia, elevated liver transaminases, dec white count
Isotretinoin: labs (baseline, throughout course)
baseline:
CBC, LFT, lipid profile, serum pregnancy test
1st month only:
repeat CBC, LFT
every month:
fasting lipid profile, serum pregnancy test
What agents are used to treat rosacea?
first line: metronidazole
sodium sulfacetamide
- clindamycin, erythromycin
- topical imidazoles, ketoconazole cream
- azelaic acid cream
- tetracyclines (abx and anti-inflammatory effects)
- isotretinoin (stage III w/ rhinophyma, rosacea fulminans – NOT recommended for ophthalmic rosacea)
Metronidazole: contraindication, ADEs
contraindication: pregnancy, nursing mothers, children
ADEs:
dryness
burning
stinging
Sodium Sulfacetamide: indications, contraindications
+/- sulfur
indication: rosacea, seborrheic dermatitis
contraindication:
sulfonamide sensitivity
What are the antifungal agents?
Triazoles (fluconazole, itraconazole)
Imidazoles (clotrimazole, ketoconazole, miconazole)
Nystatin
When/where do we use topical imidazoles? When do we not use them?
stratum corneum
mucosa
cornea by dermatophytes
candida sp infx
NOT for SQ, nail, hair infx
paronychial and intertriginous candidiasis
**also can treat seborrheic dermatitis (ketoconazole)
What are the risk evaluation and mitigation strategies associated w/ isotretinoin in females?
F must use 2 effective forms of contraception (1mo before, during, 1 menstrual cycle after discontinuation)
serum pregnancy test must be obtained w/in 2 wks before therapy
When/where do we use topical vs oral nystatin?
TOPICAL: cutaneous and mucosal candida
ORAL: oral candidiasis
vulvo-vaginal candidiasis
NOT effective against dermatophytes
What are the box warnings associated w/ immunomodulators?
malignancy (skin, lymphoma) (rare)
limit continuous long term use
limit use to areas of involvement
not indicated for <2yo
What are the immunomodulator agents? What is their MOI?
tacrolimus
pimecrolimus
calcineurin inhibitors (inhibit T lymphocyte activation, prevent degranulation of mast cells)
Tacrolimus, Pimecrolimus: indications
atopic dermatitis
off label: autoimmune dermatologic disorders (vitiligo, alopecia areata)
What agents are used in the general treatment of pruritis?
emollient (3x/d, 3min after bathing)(refrigerate to inc effectiveness)
topical steroids (w/ inflammatory conditions)
topical capsaicin (ADE: burning)
topical doxepin (ADE: anticholinergic effects, significant drowsiness)
What are some non-pharmacologic interventions for the treatment of pruritus?
cool skin - light clothes
air conditioning, humidifier
avoid topical products w/ fragrances, alcohol, wool, alkaline soap, potential allergens
tepid showers (limit bathing, use non soap low pH cleanser)
cool compress
What are the contraindications for doxepin 5% cream in the treatment of pruritus?
urinary retention
narrow angle glaucoma
**potent H1 and H2 receptor antagonist
Permethrin: indications
Pediculus humanus, Pthirus pubis, and Sarcoptes scabiei
Permethrin: directions for use
pediculosis: 1% cream rinse
scabies: 5% cream
single application
apply to body from neck down
leave on for 8-12hrs
wash off
**drug persists up to 10d following application
Ectoparasiticides
Permethrin (otc) Lindane (rx) Crotamiton (2 applications) Sulfur Spinosad (rx) Malathion (rx) Ivermectin (rx)
Why is Lindane NOT a first choice ectoparasiticide?
tx for lice, scabies
concentrates in fatty tissues INCLUDING THE BRAIN
potentially neurotoxic
can lead to seizures
What is a possible alternative treatment for lice/scabies in pregnant women and infants?
sulfur – 2 applications
Which agents reduce hyperpigmentation? How long do their effects last?
HYDROQUINONE, MEQUINOL, MBEH
- temporary lightening
- *can be sped up if use w/ tretinoin or glycolic acid
MONOBENZONE - irreversible depigmentation
**may cause hypopigmentation at sites distant from area of application
Which agents increase pigmentation?
When are they indicated?
What risks do they pose?
psoralens: trioxsalen, methoxypsoralen
photoactivated by UVA light
indication: vitiligo (repigments depigmented macules)
risks: cataracts, skin cancer
What are the 3 classes of compounds in sunscreen?
p aminobenzoic acid (most effective available absorbers in B region)
benzophenones (oxybenzone, dioxybenzone, sulisobenzone)
dibenzoylmethanes (avobenzone)
What are the 3 classes of compounds in sunscreen?
P AMINOBENZOIC ACID (most effective available absorbers in B region)
BENZOPHENONES (oxybenzone, dioxybenzone, sulisobenzone)
DIBENZOYLMETHANES (avobenzone)
What chemical in sunscreen has complete UVA coverage?
parsol 1789 (aka avobenzone)
**mexoryl - recently FDA approved - better coverage than parsol 1789
When should you apply sunscreen?
20 min before going out
replace every 2 hrs
What are the protective agents in sunblock?
What is a disadvantage of sunblock (compared to sunscreen)?
Directions for use
agents: zinc oxide paste, titanium dioxides
disadvantage: not as good UVA coverage
directions: reapply every 2 hours
What is the primary dermatologic condition in which SALICYLIC ACID is indicated?
(At what concentration is it pathologic? Caution use in which patients?)
acne
psoriasis
warts
- *>6%: destructive to tissues
- *be careful using in pts w/ diabetes, peripheral vascular dz
What is the primary dermatologic condition in which UREA is indicated?
hyperkeratosis of the palms and soles
30-50% used to soften the nail prior to avulsion
**urea can also be a humectant (inc water content of stratum corneum)
What is the primary dermatologic condition in which PODOPHYLLUM is indicated? (directions for use, contraindication)
condyloma acuminatum
cytotoxic - affinity for mitotic spindle
wash off 2-3 hrs after application
contraindication: pregnancy
What is the primary dermatologic condition in which FLUOROURACIL is indicated? (ADEs)
actinic keratoses
ADEs: erythema vesiculation erosion SF ulceration necrosis reepithelialization
inc exposure to sunlight –> inc intensity of reaction
What are the keratolytic agents? What do they do?
salicylic acid urea podophyllum resin and podophyllotoxin fluorouracil aminolevulinic acid
break down/dissolve keratin –> softening of the stratum corneum –> peeling
What are the agents use to treat warts?
salicyclic acid topical retinoids podophyllum resin imiquimod trichloroacetic acid
Imiquimod: indications
warts
actinic keratosis
BCC, SCC
lentigo maligna melanoma
Trichloroacetic Acid: indication, warning
condylomata
improper application –> skin damage, burns, swelling, pain
What are agents are utilized to increase/stimulate hair growth?
minoxidil
finesteride
bimatoprost
Topical Minoxidil:
MOI
Which form of balding is more responsive?
How long does the effect last?
MOI: vasodilation –> inc BF –> stimulation of resting hair follicles
vertex balding is more responsive than frontal balding
NOT permanent (cessation –> hair loss in 4-6mo)
Finsteride: MOI, contraindication, ADEs
blocks dihydrotestosterone
- promotes hair growth
- prevents further hair loss (androgenic alopecia)
NOT for F of child bearing age
ADEs:
dec libido
ejaculation disorders
erectile dysfunction
Bimatoprost: brand name, ADEs
aka latisse
prostaglandin analogue
ADEs:
- red/itchy eyes
- skin pigmentation
- permanent brown pigmentation of iris
What is Eflornithine and what is it indicated for?
irreversible ornithine decarboxylase inhibitor
anti-trichogenic agent
reduction of facial hair growth in women
What is the initial treatment for psoriasis?
high potency topical steroid
phototherapy
What agents are used to treat psoriasis?
dovonex tars tazarotene acitretin apremilast methotrexate biologic agents
What are the biologic agents used to treat psoriasis?
What are their contraindications?
What are the risks to use?
ADEs
TNF blockers (enbrel, humira, remicade, simponi)
Interleukin 12/23 (stelara)
contraindications:
IM
active infection
screen for TB
risks:
inc risk for infx
unknown for dev fetus/infant
ADEs: respiratory infx flu like sx injection site rxns MS, seizures, optic neuritis hemolytic anemia lymphoma
Dovonex: what is it, indication, ADE
vitamin D3 analog
indication: psoriasis
ADE: hypercalcemia
may be used in combo w/ topical steroid or in rotation
Tars: indication
dandruff, psoriasis
Tazarotene: what is it, indication, ADEs
topical retinoid
generally rx’d w/ topical corticosteroid
psoriasis
ADEs:
skin irritation
photosensitivity
Acitretin: what is it, indication
retinoid metabolite
psoriasis
What are the contraindications/warnings for acitretin?
MUST NOT be pregnant/become pregnant during and 3yrs after tx
MUST strictly avoid ethanol during and 2mo after tx
MUST NOT donate blood during and 3yrs after tx
Apremilast: what is it, indication, ADEs
PDE4 inhibitor (dec cAMP, inflammatory mediators)
psoriasis
ADEs:
diarrhea
nausea
URI
Methotrexate: what is it, indication, contraindications
folate antagonist
psoriasis
pregnancy category X:
- avoid in pregnancy, breastfeeding
- men advised not to father children during and 3mo after tx
contraindications:
low blood counts (anemia, leukopenia, thrombocytopenia)
sev liver dz
caution use:
mild liver dz, kidney dz, infections, obesity, diabetes
What are the principals of topical therapy?
efficacy: depends on potency and penetration
topical formulation: meant to enhance beneficial effects
vehicle or active ingredient may cause local toxicity
topical meds may induce systemic toxicity
What are some factors that affect penetration?
concentration thickness/integrity of stratum corneum frequency of application occlusiveness of vehicle compliance
What are the principle aims of dermatologic therapy?
Specific agent to counteract disease Reduce inflammation Relieve symptoms Promote epithelial healing Restore integrity of cutaneous barrier Prevent complications
Cleansing Agents
soaps
detergents
solvents
Anti-Inflammatory Agents
corticosteroids
noncorticosteroids
Astringents
drying agents that precipitate protein and shrink/contract the skin
Drying Agents
dry macerated skin and reduce friction by absorbing moisture
Moisturizing Agents
emollients
skin hydrators
softeners
restore water, oils to skin
help maintain skin hydration
Keratolytics
soften, loosen, facilitate exfoliation of squamous cells of epidermis
Antipruritics
protect against stimulation of scratching, friction, changes in temp
What are the principal pharmacologic effects of topical therapy?
Anti-inflammatory
Immunosuppressive
Inhibition of Mitosis
Anti-exudative
Cleansing
Symptomatic relief of pruritis and pain
Protection from mechanical, thermal, actinic and chemical irritation
Relief of dryness and chapping by increasing water content of keratin
Modification of microbial environment and population of the skin
Dissolution of the keratin layer
Destruction of pathologic tissue
