Acne Flashcards
Size of papules
Small, tender red bymps, elevation less than 0.5cm is diameter
Description of pustules
Less than 0.5cm in diameter, filled with purulent white or yellow pus
Nodule description
Red lesion greater than 0.5cm in both width and depth
Cyst description
Nodule containing a liquid or semisolid that can be expressed
Mild acne
Several inflamed pimples
- <20 comedones
- <15 inflammatory lesions
- Or total lesion count <30 that are not all inflamed
Moderate acne
Many inflamed pimples and pustules (visible accumulation of pus)
- 20 - 100 comedones
- 15-50 inflammatory lesions
- Or total lesion count 30-125 that are not all inflamed
Severe nodular acne
Inflamed pimples and pustules with a few deep nodular lesions
- >5 pseudocysts (solid mass of skin, can be raised or felt under skin)
- Total comedo count >100
- Total inflammatory count >50
- Or total lesion count >125
Severe cystic acne
Many nodular lesions with signs of scarring
Why is it not recommended to use topical antibiotics alone?
Risk of resistance, recommended to use clindamycin with benzoyl peroxide.
Management for mild acne
- Benzoyl peroxide (2.5-10%)
- Adapalene 0.1-0.3%
- Tretinoin 0.025%-0.1%
- Topical BPO + Topical Antibiotic/Retinoid
- Topical BPO + Topical Antibiotic + Retinoid
Benzoyl Peroxide MOA
Antibacterial (release free oxygen radicals, damage bacterial cell walls); Mildly comedolytic (exfoliate and open pores)
Adapalene MOA & Side effects
MOA: Anti-inflammatory (more than tretinoin); Comedolytic
SE: Dryness, peeling, irritation, redness, photosensitivity
Management of moderate acne
- Oral antibiotics + Topical retinoid + BPO w/wo topical antibiotic
- Topical combination therapy (Abx+BPO w/wo Retinoid)
Severe acne
- PO Abx + Topical combination therapy
- PO Isotretinoin
Doxycycline SE and Administration
SE:
- Gastric irritation
- Vaginal candidiasis
- Photosensitivity
To take with a full glass of water and stay upright for 30mins. Space apart from milk, dairy products, antacids, and cation-containing products by at least 2 hours.
Contraindications of Doxycycline
Pregnancy;
≤8 years old due to permanent discoloration and hypoplasia of teeth (max duration <21 days in <8yo)
Isotretinoin MOA
Shrink oil glands; reduce acne bacteria; prevent clogs; reduce inflammation
Isotretinoin dose
0.5-1.0 mg/kg/day for ~20 weeks (complte remission often in 16-24w), with goal cumulative dose of 120-150mg/kg
Initiate at 0.5mg/kg/d in 2 divided doses or OD for better adherence, then increase to 1mg/kg/d after 1st month as tolerated
Side effects of Isotretinoin
- Initial transient worsening flare of acne during 1st month of treatment. Should start to clear 1-2 months after initiation.
- Dryness of mucous membranes, dry skin, itching
- Hair loss
- Headache, Muscle and joint pain
- Photosensitivity
Rare:
- elevated ALT/AST
- Hyperlipidemia, HyperTG
- Depression and suicide (controversial)
Things to note with Isotretinoin (ABCDEF)
- Vitamin A: Avoid vitamin A supplement, increases risk of vitamin A toxicity which can also worsen dryness
- Blood donation: Can only donate at least 1 month after last dose
- Contraception: Teratogenic, ensure effective contraception used at least 1 month before, during and up to 6 weeks after therapy
- Dryness (use lip balm, lubricating eye drops, saline nasal spray/petroleum jelly to nostrils, moisturizer
- Exposure to sunlight: avoid cosmetic skin treatment and apply sunblock, wear long sleeve and pants
- Full lipid and liver profile: LFT and serum lipids before initiation, 1 month after and 3months after to assess suitability to continue (avoid alcohol consumption)
