A23. Acne and its treatment

Common acne = Acne vulgaris
(comedo/comedones = plugged hair follicle (pore))
Risk factors
- Genetic predisposition
- Hormonal changes
  - Puberty
  - Menstrual cycle
- Certain foods
- Smoking
- Skin products that block pores
Pathomechanism
- Hyperactivity of sebaceous glands
- Hyperkeratosis of follicular keratinocytes
- Bacterial hypercolonization
  - Propionibacterium acnes (= cutibacterium acnes)
- Inflammation
Clinical features
- On face, shoulders, upper chest, back
- Primary lesions
  - Non-inflammatory acne – comedonal acne
    - Closed comedones = whiteheads
      - Small papules that contain whitish material
      - The whitish material is keratin and sebum
    - Open comedones = blackheads
      - Small papules with black material
      - The black material is oxidized keratin and sebum
  - Inflammatory acne
    - Papular acne
    - Pustular acne
    - Nodular acne (> 5 mm)
- Secondary lesions
  - Erythema
  - Hyperpigmentation
  - Scarring
    - Hypertrophic scars
    - Depressed scars
    - Pitted scars
Special types of acne
- Acne inversa = hidradenitis suppurativa
  - Inflammation of hair follicles due to physical blockage by skin folds, etc
- Acne fulminans
  - Sudden onset, very severe acne
  - In teenage boys
Diagnosis
- Anamnesis
- Clinical examination
- Laboratory examinations
  - Exclude hyperandrogenism, like PCOS, CAH, androgen-producing tumors
Treatment
- Options
  - Topical benzoyl peroxide
    - Comedolytic
    - Bactericidal
  - Retinoids
    - Oral or topical
    - Tretinoin, isotretinoin, adapalene
    - Normalize keratinocyte differentiation
    - Decrease sebum production
    - Highly teratogenic
      - Females must produce negative pregnancy test and use at least one, optimally two methods of contraception
    - Hepatotoxic
      - Liver enzymes, cholesterol must be monitored
  - Antibiotics
    - Oral (doxycycline, minocycline)
    - Topical (erythromycin, clindamycin)
    - Bactericidal
    - Decrease inflammation
  - Oral contraceptives
    - In females
    - Can be added in treatment failure
  - Topical combination therapy
    - Benzoyl peroxide + topical retinoid
    - Benzoyl peroxide + topical antibiotic
    - Benzoyl peroxide + topical retinoid + topical antibiotic
- Treatment algorithm
  - Mild cases
    - Topical benzoyl peroxide
    - Topical retinoid
    - Topical combination therapy
  - Moderate cases
    - Topical combination therapy
    - Oral antibiotic + topical combination therapy
  - Severe cases
    - Oral retinoid