Module 3A Dermatology Flashcards
Describe ABCDE’s of skin cancer
A- Asymmetry
B- Borders are irregular
C- Color changes (tan,brown,black,white,red,blue)
D- Diameter (usually >6mm, size of pencil eraser)
E- Evolution (keeps changing appearance)
Guidelines for sunscreen
- Use spf 15 or more if more than 20min exposure
- Apply 30min prior and then every 2hr
- Choose broad spectrum for UVA & UVB rays
Does increasing spf significantly increase protection?
NO, 15 absorbs 93% & 34 absorbs 97%
Which sunscreens sweat off more easily?
Gel
Water resistant or waterproof?
WATER RESISTANT (for 40 or 80 min)
What are the benefits of sunscreen?
Protect against sunburn, aging, & some cancers
Most effective treatment for contact dermatitis?
PREVENTION
What are the two types of contact dermatitis?
- ICD- Irritant contact dermatitis - exposure to agent that is toxic to skin; usually localized
- ACD- Allergic contact dermatitis- exposure to antigen; more diffuse
What is atopic dermatitis?
Eczema - a form of allergic dermatitis; chronic inflammatory condition
Three goals of drug therapy for contact dermatitis.
- Restoration of normal epidermal barrier
- Treatment of inflammation of skin
- Control of itching
What three factors determine type of drug tx for contact dermatitis?
- Protection/barrier function
- Delivery of drug to skin
- Cosmetic appearance with tx
In contact dermatitis, _____________ determines tx.
severity
Which topical bases(2) offer the best delivery and protection barrier for contact derm?
Ointments and gels- most potent and lubricating
Which topical base is more cosmetically desirable, but less effective? Why?
Creams, because they are less greasy; water based and cause more drying.
What is a lotion?
A dilute cream
What is a solution? When and why is it used?
An alcohol based liquid; useful for scalp tx because it doesn’t coat the hair.
What do barrier creams and moisturizers do?
Increase skin hydration.
What 4 types of medication are available for tx of contact dermatitis?
Topical corticosteroids, Immunosuppressant, Systemic corticosteroids, antihistamines.
When are immunosuppressants used for contact derm and what are the drawbacks?
- Used for chronic atopic dermatitis
- Taken on a regular basis; not antipruritic
- Take several weeks to take effect and are associated with skin cancer and lymphoma (cancer in peds, but rare)
The mainstay of therapy for Contact derm is ____________.
Topical corticosteroids
Topical corticosteroids should be applied how often?
How long for use in adults? children?
Apply BID; No longer than 2 weeks in adults and 1 week in children.
Where should the lowest potency glucocorticoid always be used?
Face and intertriginous areas (areas where skin touches skin)
Topical glucocorticoids relieve _________ & ____________.
inflammation and itching
Contact derm: 1st, 2nd, and 3rd line?
- 1st- low-potency topical with oral antihistamine
- 2nd- increase potency of topical
- 3rd- Oral corticosteroid on tapered-dose regimen
What does application of an occlusive dressing do for contact derm topical tx?
Increases absorption and penetration by increasing hydration
Adverse effects of topical corticosteroids.
- *Atrophy of skin
- Also acne-like eruptions on the face, ecchymosis, striae, telangictasia, acne, hypertrichosis, cataract formation (when used around eyes)
Can systemic toxicity occur with topical corticosteroids? If so, what is the concern?
Yes, growth retardation and adrenal suppression
What are the 4 actions of systemic corticosteroids?
- Inhibit cytokine & mediator release
- Attenuate mucus secretion
- Up-regulate beta-adrenergic receptors,inhibit IgE synthesis, decrease microvascular permeability
- Suppress influx of inflammatory cells
What type of dosing is used for systemic corticosteroids?
Tapered and burst. Taking less than 2 weeks may result in rebound dermatitis.
What patients are systemic corticosteroids contraindicated for?
- Systemic mycoses and receiving vaccinations
What are the adverse effects of systemic corticosteroids?
Mask infection, GI upset, mood changes, sleep disturbance, increased appetite
Goals of therapy for acne & rosacea
Minimize scarring and improve appearance
First line therapy for acne & rosacea
Skin care, avoid cosmetics, water based moisturizers, perfume free
Describe comedonal, mild inflammatory, moderate inflammatory, and severe cystic acne.
Comedonal: open and closed comedones
Mild Inflammatory: Papules
Moderate Inflammaory: Pustules, cysts
Severe cystic: Cysts, nodules, “ice-pick” scarring
List thre topical retinoids (comedolytics) and explain how they work.
Tretinoin (acid form of vit. A - causes peeling of skin & erythema), Adapalene gel (less irritating than retinoic acid), and Tazarotene clear mild to moderate acne by normalizing hyperproliferation of epithelial cells in hair follicles.
Are topical retinoids absorbed sytemically?
No.
Name 3 topical antibiotics for acne and describe how they work.
Benzoyl peroxide (category C in pregnancy) when combined with topical antibiotic s reduces bacterial resistance. Clindamycin, and erythromycin help clear mild to moderate acne by suppressing growth of Propionibacterium acnes.
Name 3 keratolytic agents and decscribe what they do.
Salicylic acid, sulfur, and benzoyl peroxide promote shedding of the horny layer of skin.
What is used when improvement is not achieved with topical therapy (2nd line)?
Oral antibiotics are used for moderate to severe acne.
What is the most commonly used oral antibiotic for acne? What other oral antibiotics are used? How do they work?
Tetracycline. Erythromycin, minocycline, and doxycycline. They suppress growth of Propionibacterium acnes.
What oral drug is reserved for severe acne (3rd line)? What does it do?
Isotretinoin (Acutane). It is a retinoic acid derivative that decreases sebum production, follicular obstruction, and the number of skin bacteria; also has anti-inflammatory action.
What are the adverse effects of Isotretinoin?
Teratogenicity- 25 fold increase in fetal abnormalities and 50% exposed children will have subnormal intelligence. Cholesterol and triglyceride elevations, dry skin and mucous membranes, nosebleeds, inflammation of lips and eyes, and pain, tenderness, or stiffness in muscles, bones, and joints.
What safeguards are put in to place due to the teratogenic effects of Isotretinoin?
Prescribers must be registered with the iPledge program. Two negative pregnancy tests prior to starting tx. Two forms of contraception must be used. Pregnancy should be avoided for one month after completing tx.
What other medication can be used for acne?
OCP’s - ethinyl estradiol withnorgestimate (Ortho Tri-cyclen, Estrostep, Yaz). Reduce both comedonal & inflammatory acne.
When should OCP’s be used for acne?
Female, at least 15 y/o that have started menarche. Use as 3rd line after trying topical keratolytic agents first, and combined antibiotic with benzyl peroxide second.
What condition seen in adults mimics acne? What triggers it?
Rosacea. spicy foods, stress, alcohol.
What is used to treat Rosacea?
Metronidazole cream, gel or lotion (1st line). Benefits seen in 3 wks with full effect in 9 wks.
What are 2nd and 3rd line tx for rosacea?
Oral abx and oral isotretinoin with poss. referral to derm
1st and 2nd line for Psoriasis when 10% is affected?
1st: High to very high potency topical corticosteroids applied with use of occlusive dressing BID for 2wks; emollients as adjunct therapy.
2nd: if good response from 1st, provide 1wk rest from steroids and repeat 2 more rounds OR taper the high potency topical corticosteroids to once or twice a week and add a vit D analog BID
HSV 1 1st and 2nd line of tx?
1st: topical acyclovir 5% or penciclovir 1%
2nd: systemic therapy with acyclovir, famciclovir, or valacyclovir - contraindicated in renal disfunction
