Acne Vulgaris and Perioral Dermatitis (PHARM) Flashcards
Definition of Acne Vulgaris
Common chronic inflammatory disorder of the sebaceous glands and hair follicles of the skin, occurs usually in teens (8-18 yrs), resolves by 25
-Uncommon to have first outbreaks 20-25 in women
Key features of acne vulgaris
-Inflammatory lesions, papules, pustules, cysts
-Non-inflammatory lesions comedones
-Scarring
-Lesion count
-Face, neck, upper back and chest
When diagnosing acne vulgaris, what are the two main conditions you need to rule out?
-Acne rosacea
-Perioral dermatitis
What is the etiology of acne vulgaris?
-Increase activity of sebaceous glands in the face, upper back and chest
-Sensitivity to androgens
-Acne originates in the pileosebaceous unit
What is a pilosebaceous unit?
-Consists of a hair follicle and a sebaceous gland that is connected to the surface of the skin by a duct through which the hair shaft passes
What does the sebaceous glands produce?
-Sebum (a fat and wax mixture) to maintain proper hydration of the skin and hair
Pathophysiology of acne vulgaris
- Increase sebum production secondary to androgen
- Abnormal follicular keratinization that causes a microcomedone (plug)
- Proliferation of p. acnes
(propionibacterium acnes gm+) causes free fatty acids leading to inflammation/irritation
What happens when P.acne proliferates?
-Liberates lipases that hydrolyze triglycerides of the sebum to irritating free fatty acids and causes inflammation
What are the open and closed comedomes?
-Open=black heads-oxidized
-Closed: whiteheads, precursor of inflammatory lesions
Three classifications of acne
- Comedonal: open and closed comedones
- Inflammatory: papules and pustules
- Nodulocystic: nodules and cysts, describe the severity and presence of scarring, pain
Examples of topical corticosteroids in each potency
-High potency: clobetasol 0.05%
-Medium potency: betamethasone 0.05%
-Low potency: hydrocortisone 0.5% or 1%
Example of Calcineurin inhibitor creams
-Tacrolimus 0.03, 0.1% (Protopic)
-Pimecrolimus cream 1% (Elidel)
Risk factors for acne vulgaris
-Stress
-Premenstrual flares
-Improper cleansing of hair and skin
-Local friction
-Androgens, barbiturates, corticosteroid, haloperidol, lithium, phenytoin, oral contraceptives (levonorgestrel), bromides, iodines
What are the treatment goals in acne vulgaris?
- Reduce keratinization process
- Decrease sebum production
- Reduce microbial flora and decrease enzyme
-takes 8-12 weeks to see improvement
What is perioral dermatitis?
-Papules and pustules around mouth area
-No white or black heads are seen
-Can be caused by steroid or cosmetic cream
Treatment for normalization of follicular keratinization
-Benzoyl peroxide
-Topical retinoids
-Oral Isotretinoin
-Hormonal therapy
Treatment for antibacterial
-Antibiotics topical and oral
-Benzoyl peroxide
Treatment for anti-inflammatory
-Benzoyl peroxide
-Topical retinoids
-Antibiotics
-Oral isotreinoin
Treatment for decrease sebum production
-Oral isotretinoin
-Hormonal therapy
Benzoyl Peroxide mechanism of action
-Antibacterial
-Reduces free fatty acids
-Prevents new comedones
-Reduces resistance of p.acnes when combined with topical and oral antibiotics
Disadvantages of Benzoyl Peroxide
-Dryness and irritation redness for first 1-2 weeks
-Contact dermatitis so do a trial test first
-Apply benzoyl in AM and tretinoin in PM
Topical Retinoid, Tretinoin mechanism of action
-Decreases cohesiveness of follicular epithelial cells
-Increases cell turnover results in explosion of existing comedones, unplugs the pore (most effective comedolytic)
-Thins skin
-apply HS
-Category C in pregnancy
Disadvantages of Topical Retinoid
-Irritation, redness, peeling 2-10 days post usage
-Need suncreen
-Flare of acne appears 3-6 weeks and clears by 8-12 weeks
What is Tazarotene?
-Synthetic retinoid, once metabolized it converts to tazarotenic acid
-Most irritating and potent
-Use sunscreen
-Don’t use with peroxide
-Use HS
-Category X in pregnancy
What is topical Adapalene ?
-Synthetic naphthoic acid derivative with retinoid activity
-Inhibits arachidonic acid metabolism, less inflammatory
-Less irritating than retinoids
-More effective than retinoid
-Differin 0.1% at bedtime
-Category C in pregnancy
Topical antibiotics mechanism of action
-Elimination of P.acnes from follicle
-Decrease fatty acids production
-Decrease inflammation by suppressing leukocyte chemotaxis
-Avoid using it as the only treatment to prevent bacterial resistance
What are examples of topical antibiotics?
-Topical clindamycin (Rare case of pseudomembranous colitis)
-Topical erythromycin (safest in pregnancy, greatest resistance risk)
Dapsone 5% gel
-sulfone
-may use in patients with sulphonamide allergy
-Anti-inflammatory effect
-Remote risk of hemolysis if positive for G6PD deficient
-Used in combination with benzoyl peroxide can lead to yellow orange discolouration of skin and hair
-can be used if cannot tolerate other treatments
-$$$
What is the mechanism of action of oral antibiotics in acne?
-Eliminate P.acnes from follicle
-Tetracyline inhibit chemotaxis so anti-inflammatory
-Best for moderate to severe inflammatory acne
-Pair with Benzoyl peroxide and retinoid acid
-Switch antibiotics if no response in 6 weeks
-Max 3 months of use oral antibiotics
-Discontinue once acne improves
What are the examples of oral antibiotics for acne?
-First choice: tetracycline, contraindicated in pregnancy
-First line: doxycycline, lipid soluble, lower dose to act as anti-inflammatory
-Used in patients unresponsive to tetracycline: minocycline
-Second line: erythromycin, used in pregnancy
-Occasional use: Trimethoprim-sulfamethoxazole, can result in Stevens Johnsons syndrome, to treat gram negative folliculitis
What are the specific side effects of minocycline?
-Blue black color changes in scars (check inside the mouth)
-Drug induce lupus reversible in 16 wks
-Liver reactions
Which drugs erythromycin interact with?
-By p450 inhibition: anticoagulants, digoxin, carbamazepine, statin, theophylline
Mechanism of action for Isotretinoin ?
-Decrease sebum production this decrease p.acne and inflammation
-Normalize keratinization
-Helps in nodulocystic acne
Side effects of Isotretinoin?
-Chapped lips+++
-Increase in cholesterol
-Abnormal liver function
-Increase intracranial pressure
-Corneal opacities, conjunctivitis
-Musculoskeletal pain
-Skeletal hyperostosis (excessive bone growth)
-DO NOT start if suicidal ideation
-Teratogenic (NEED two methods of contraception one month before, during and one month after therapy)
What blood works are you monitoring for Isotretinoin?
-CBC
-LFT
-Lipids (baseline, 4, 8 weeks)
-Pregnancy negative before during after
Hormonal therapy mechanism of action in acne ?
-Estrogen decrease the amount of circulating androgens
-Increase serum binding hormone globulin (so less testosterone)
-If hormone therapy not use, can use Spironolactone as a androgen receptor blocker
