dermatology Flashcards
dermatology
-rule of thumb for derm conditions:
-if its wet or oozing -> make it dry
-if its dry -> make it wet or moist
diaper rash
What causes diaper rash?
-Diapers act like occlusive dressings
-Primary reason for diaper rash is urine and feces in diaper
-urea, ammonia, pH, enzymes
-Systemic antibiotics may also predispose child to diaper rash due to superinfection
-Etiology of diaper rash
-Yeast: most common cause – Mostly due to candida albicans species
-Bacterial: 2nd most common cause - Mostly due to S. aureus, group A S. pyogenes
how can we prevent diaper rash
-Keep area clean and as dry as possible
-Powder or cornstarch
-Frequent diaper changes
-Diaper should be loose fitting, ventilated
-Change to cloth if needed
-Remove diaper and leave off as time permits
-Wash with water or mild cleanser like Cetaphil
-Use cool air to dry buttocks
diaper rash: protective barrier
-A&D oint
-Petrolatum (Vaseline)
-Zinc oxide!
-Desitin (contains zinc! oxide and emollient)
-Some contain protectant + drying agent + anti-microbial + vitamins
topical steroids: diaper rash
-Do little to treat rash – they are beneficial for their anti-inflammatory effect
-Caution b/c they can cause adrenal suppression if too much gets absorbed
-not treating any fungus or bacteria
diaper rash tx: yeast
-“red satellite lesions”
-Topical antifungal
-Nystatin (Mycolog) – powder, cream, oint
-Nystatin + triamcinolone (Mycolog II) – cream , oint
-Clotrimazole (Lotrimin) - cream
-Clotrimazole + betamethasone (Lotrisone) – cream
-NEW combination product
-Zinc oxide, petrolatum & 0.25% miconazole (Vusion)
diaper rash tx: bacteria
-(usually staph or strep) – “yellowish, fluid-filled pustules, honey-colored, crusty”
-Mild infections – may benefit from topical product like bacitracin (1st) or mupirocin (2nd) !
-More severe infections – Must treat with appropriate systemic (PO) antibiotics (beta-lactams are very effective)
-Combination therapy (Topical AND PO) is most effective and is often utilized in clinical practice
butt paste
-Includes the following ingredients
-Zinc oxide
-Aquaphor, A&D oint or petrolatum
-Cholestyramine (Questran)
-Cholestyramine binds uric acid, keeps pH at normal levels, zinc and A&D provide protective barrier.
-NOT for prevention -> For treatment only
poisons
-3 main types:
-ivy
-sumac
-oak
-tx for all types is similar
-if you are sensitive to one type - you are sensitive to all
poisons- ivy, oak, sumac
-Rhus Dermatitis – delayed hypersensitivity rxn occurring 12 – 72 hrs after exposure
-Urushiol – chemical secreted by bruised plants
-Primary exposure – direct contact to bruised portion of plant that exudes urushiol
-Secondary exposure – contact with exposed pets, contaminated clothing, smoke from burning plants
-Not transmitted via fluid vesicles/blisters
-The condition is self-limiting ->14-20 d
-Symptoms include:
-Severe itching
-Burning sensation
-Secondary infection can occur
-Caused by scratching – bacteria enter broken skin
poisons- ivy, oak, sumac: tx goals
-Protect damaged skin
-Relieve pain and itching, Prevent secondary infection
-Wash area immediately w/ soap and alcohol
-Reduce pain and/or itch
-Barrier products
-Bentoquatam (Ivy Block)
-Zanfel – OTC wash – not recommended
poison ivy, oak, sumac tx: soaks, baths, mild dressings
-tx depends on severity
-tx of mild and moderate cases:
-Colloidal oatmeal (Aveeno) – bath, transient relief
-Aluminum acetate (Burrow’s soln) – moist/wet dressings, reduce itch, mild astringent
-If there are facial lesions – Use moist/wet dressings – NOT lotions (difficult and painful to remove once dry)
poison ivy, oak, sumac tx: topical
-mild to moderate:
-Calamine (calamine, Fe oxide, Zn oxide) -> make you pink
-Local anesthetics (ie. Caladryl = calamine + pramoxine)
-Antihistamines (Benadryl cream):
-May sensitize skin
-!!!!!!Generally not effective – diphenhydramine does not penetrate skin & may irritate further
-Camphor, menthol, phenol, EtOH:
-Promotes drying of vesicles
-Camphor & menthol - “cooling” effect
-Phenol & EtOH - Antibacterial
-Aluminum acetate solutions
-Steroids
-Do NOT use ointments while vesicles are present and/or weeping b/c they can form a barrier and seal moisture in - the vesicles need to dry
poison ivy, oak, sumac tx: severe
-widespread or eye involvement
-Oral Antihistamines – anti-itch
-Diphenhydramine – 25-50mg PO qid prn
-ADR: sedation, dry mouth
-Oral Glucocorticosteroids – anti-inflammatory
-Common dose: Prednisone PO 7-21 d, taper off
-Some practitioners might use in moderate cases
-ADRs - see glucocorticosteroids handout
-Oral Antibiotics - If infections occurs
-Treat for staph (most common in skin infections) – cephalosporins and penicillins mainstay,
acne
-Acne is stimulated by testosterone and its metabolite - dihydrotestosterone
-Pathogenesis is multifactorial
-Bacterial - P. acnes
-Irritants
-Touching your face
-Makeup (lanolin and emollients trap dirt)
-Foods (certain individuals)
acne general treatment
-Cleanse skin BID w/ mild cleanser (Cetaphil) and pat dry
-Use coarse cloth or other sponges to exfoliate skin
-Astringent – closes pores helps prevent dirt from entering
-Medication as necessary
pharm tx of acne: choices
Topical Benzoyl Peroxide
Topical Salicylic Acid
Topical Retinoids
Miscellaneous topicals
Topical antibiotics
Oral Antibiotics
Oral isotretinoin (Accutane)
Oral contraceptives
acne: benzoyl peroxide
-MOA - Causes desquamation – increase turnover of epithelial cells, promotes healing, May be bacteriostatic or bacteriocidal
-Precautions - Do not use around mouth, eyes or lips. Some pts are hypersensitive.
-ADRs
-Drying, Peeling, Stinging
-May bleach clothing or linens (use white pillow cases)
acne: salicylic acid
-clearisil pads
-MOA - Keratolytics – helps remove upper layer of dead cells
-ADRs
-Drying, peeling
-Other indications: higher concentrations of salicyclic acid (10-15%) are used for wart removal
acne: retinoids
-vitamin A derivatives
-MOA - increases epithelial cell proliferation, reduces comedo formation
-Precautions - AVOID sun – use SPF 30-45 – minimize exposure. Do not use too close to eyes, mouths, lips.
-ADRs – erythema, dryness , peeling, scaling, itching, crusting, photosensitivity, pigmentation changes (bleaching).
-Examples:
-Tretinoin (Retin-A, Renova, Avita) (D) gel and cream
-Tazarotene (Tazorac) (X) gel and cream
acne: adapalene
-(Differin 1% gel) (C)
-otc
-mild to moderate acne
-MOA - Retinoid-like compound, binds to different retinoid type receptors
-ADRs – similar to other retinoids, local skin irritation, not shown to be teratogenic in rodents, but no human studies
acne: azelaic acid
-MOA - not fully determined, but may have antimicrobial activity against P. acnes and blocks conversion of testosterone to dihydrotestosterone
-ADRs - erythema, dryness
acne: topical antibiotics
-MOA - antimicrobial activity against causative organisms
-ADRs - Burning stinging, drying, peeling, erythema
-Dosed – 2-6xd – resistance rare due to minimal systemic absorption
-resistance if pt is not consistent
-Examples:
-Erythromycin (B)
-Erythromycin + benzoyl peroxide (C)
-Sodium Sulfacetamide (C)
-Clindamycin (B) gel, cream, lotion, soln, disposable pads
-Combo w/ benzoyl peroxide (Duac Gel)
acne: oral antibiotics
-MOA - antimicrobial activity against causative organisms
-moderate to severe
-Precaution - May increase risk of resistance due to chronic usage
-ADRs include
-Nausea, vomiting, diarrhea and many others (more detail to be provided in antimicrobial lecture)
-Vertigo (primarily with minocycline)
-Contraceptive failure of BC pills (use alternate form of BC)
-Examples
-Tetracyclines:
-Doxycycline (D)
-Minocycline (D) *- go to QD
-Macrolides- Erythromycin (B)- less likely - if pregnant
acne: isotretinoin
-oral retinoid
-MOA - reduce sebaceous gland size, regulates cell proliferation and differentiation
-DOSE: 0.5 – 1 mg/kg/day for 15-20 weeks. May repeat x 1 after 2 months off
-ADR’s - dryness & itching of skin and mucous membrane, HA, depression, hyperlipidemia, increase LFT’s, alopecia, myalgia, hematologic ADRs, ocular ADRs, photosensitivity, increase suicide risk
-Used only for severe cases – best treatment
-Need to sign informed patient consent prior to receiving and cannot be pregnant or get pregnant
-cystic acne
acne: OCP
-females only
-MOA - Increased estrogen helps counterbalance the high testosterone levels which cause acne
-Estrogen alone or Estrogen / Progesterone combo
-With combo want high estrogenic activity and low androgenic activity (tricycline brands are good)
-ADRs – PMS like symptoms, bloating, weight gain
-Use for women >18yo, not planning pregnancy
drugs that CAUSE acne
-Hormones -Gonadotropins, Anabolic steroids, Corticosteroids
-Anti-epileptic drugs
-TB drugs- INH, Rifampin
-Miscellaneous- Lithium, Cyclopsorine, Iodine
psoriasis
-No cure for psoriasis
-Treatment can be defined as acute or chronic
-Factors influencing treatment selection
-Age of patient
-Type of psoriasis
-Site and extent of involvement
-Previous treatment
-Coexisting diseases
-Treatment goals include:
-Reduce severity
-Palliative treatment
tx of acute psoriasis
-Treat the severely erythematous lesions
-Goal is to soothe irritation, use non-medicated topicals
-Aquaphor
-Cold cream
-Lac-hydrin
-Eucerin
-May also use topical steroids
tx of chronic psoriasis
-Topical Corticosteroids
-Anti-inflammatory
-Antipruritic
-Vasoconstrictor
-Immunosuppressive
tx of chronic psoriasis: topical corticosteroids
-Start with super high potency (class 1 or 2) BID x 2-3wks
-After high potency treatment, change to Pulse treatment (2 days on then 5 days off) OR change to lower potency steroid
-Halogenated or fluorinated steroids improve absorption -> !DO NOT use on face, perineum or mucus membranes
-Non-Fluorinated steroids can be used on face, eyelids, perineum and mucous membranes
-Super potent – do not use on children or elderly due to increased systemic absorption (children: skin not keratinized, elderly: skin is thin)
-Super Potent - Avoid use in flexural areas: groin, axilla, popliteal and antecubital fossa (areas tend to be warm and moist – added absorption) – if used minimize to less than 2wks, switch to lower potency
-Super potent – may inhibit HPA axis
topical corticosteroids: psoriasis: ADRs
-Thinning
-Tearing (due to thinning)
-Bruising of skin
-Acne
-Hypopigmentation -blanching due to vasoconstriction
-Infection (immune system suppressed)
-Contact dermatitis