Acne

Question 1

Size of papules

Answer 1

Small, tender red bymps, elevation less than 0.5cm is diameter

Question 2

Description of pustules

Answer 2

Less than 0.5cm in diameter, filled with purulent white or yellow pus

Question 3

Nodule description

Answer 3

Red lesion greater than 0.5cm in both width and depth

Question 4

Cyst description

Answer 4

Nodule containing a liquid or semisolid that can be expressed

Question 5

Mild acne

Answer 5

Several inflamed pimples
- <20 comedones
- <15 inflammatory lesions
- Or total lesion count <30 that are not all inflamed

Question 6

Moderate acne

Answer 6

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

Question 7

Severe nodular acne

Answer 7

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

Question 8

Severe cystic acne

Answer 8

Many nodular lesions with signs of scarring

Question 9

Why is it not recommended to use topical antibiotics alone?

Answer 9

Risk of resistance, recommended to use clindamycin with benzoyl peroxide.

Question 10

Management for mild acne

Answer 10

• 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

Question 11

Benzoyl Peroxide MOA

Answer 11

Antibacterial (release free oxygen radicals, damage bacterial cell walls); Mildly comedolytic (exfoliate and open pores)

Question 12

Adapalene MOA & Side effects

Answer 12

MOA: Anti-inflammatory (more than tretinoin); Comedolytic

SE: Dryness, peeling, irritation, redness, photosensitivity

Question 13

Management of moderate acne

Answer 13

• Oral antibiotics + Topical retinoid + BPO w/wo topical antibiotic
• Topical combination therapy (Abx+BPO w/wo Retinoid)

Question 14

Severe acne

Answer 14

• PO Abx + Topical combination therapy
• PO Isotretinoin

Question 15

Doxycycline SE and Administration

Answer 15

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.

Question 16

Contraindications of Doxycycline

Answer 16

Pregnancy;
≤8 years old due to permanent discoloration and hypoplasia of teeth (max duration <21 days in <8yo)

Question 17

Isotretinoin MOA

Answer 17

Shrink oil glands; reduce acne bacteria; prevent clogs; reduce inflammation

Question 18

Isotretinoin dose

Answer 18

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

Question 19

Side effects of Isotretinoin

Answer 19

• 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)

Question 20

Things to note with Isotretinoin (ABCDEF)

Answer 20

• 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)