Acne Vulgaris

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Acne Vulgaris

• Michelle Adams, MD
• April 14, 2004

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Myths about acne

• Not caused by a failure to clean skin
• Aggravated w/ vigorous scrubbing
• Unrelated to dietary factors

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Background on Acne

• Pilosebaceous units
• Hair and sebaceous glands
• Located on the face, upper chest, back
• Sebaceous Glands
• Produce sebum
• Stimulated by elevated levels of circulating
  androgens

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Pathogenesis of Acne

• Multifactorial
• Excessive sebum production
• Microbial proliferation
• Inflammation
• Abnormal desquamation of the follicular
  epithelium leading to accumulation of keratinized
  cells

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Pathogenesis of Acne

• Pilosebaceous follicles are plugged w/ excess
  sebum accumulated keratinized cells leading to
  microcomedo.
• Process continues leading to comedones.
• Propionibacterium acnes proliferates, secreting
  chemotactic factors resulting in inflammatory
  lesions (papules pustules).
• P. acnes induces proliferation of keratinocytes
  adding to the excessive desquamation.

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Comedonal Acne

• Open comedones or blackheads.
• Closed comedones or whiteheads.

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Scattered papules pustules
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Points of Attack on Acne

• Excessive sebum production
• Excessive epithelial desquamation leading to
  accumulation of keratinized cells
• Proliferation of P. acnes
• Inflammation

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Topical Acne Therapies

• No single therapy treats all 4 pathogenic
  factors.
• Recommended for mild to moderate acne, especially
  when limited to the face.
• Advantage avoid possible side effects from
  systemic therapies.
• However, in order to maximize therapy, topicals
  must be applied to entire affected area, not used
  as a spot treatment.
• Does not help reduce sebum production.

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OTC Topical Therapies

• Benzoyl peroxide (QD BID)
• Only mild comedolytic properties
• Reduces colonization of skin surface
• Causes skin irritation
• Can bleach clothing
• Salicylic acid
• Keratolytic properties break down follicular
  plugs reduce follicular desquamation ?
  decreases comedones
• Causes skin irritation

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Topical Retinoids

• Treatment of choice for comedonal acne
• Reduces epithelial desquamation
• Inhibits new microcomedone formation
• Promotes drainage of comedones
• Side effects phototoxicity, erythema, dryness,
  burning
• Tretinoin
• Adapalene (3rd generation)
• Less skin irritation (due to anti-inflammatory
  activity)
• Faster onset of action

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Topical Antibiotics

• For tx of papulopustular lesions
• Clindamycin Erythromycin
• Mild comedolytic effect
• Mild anti-inflammatory effect by suppressing
  chemotaxis
• Can be used in combination w/ benzoyl peroxide.

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Azelaic Acid

• Produced by fungus (pityrosporum ovale).
• Inhibits DNA synthesis of keratinocytes.
• Decreases microcomedo formation.
• Antimicrobial activity against P. acnes.
• Decreases hyper pigmentation from acne.
• Apply cream twice daily.

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Systemic Acne Therapies

• For moderate to severe inflammatory acne
• For acne unresponsive to topical therapy
• For acne predominately on trunk

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Oral Antibiotics

• Decreases P. acnes
• Decreases FFAs and thereby their comedongenic
  proinflammatory properties
• Inhibits neutrophil chemotaxis, thereby
  decreasing inflammation
• May take 6-8 wks before improvement is noted.
• Once new inflammatory lesions have ceased to
  develop, then can slowly taper antibiotic off
  switch to topical maintenance therapy.

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• Tetracycline
• 250 to 500mg BID
• Food decreases its absorption
• ADRs photosensitivity, GI upset, pseudotumor
  cerebri
• Minocycline
• 50 to 100mg BID
• Antacids dairy decrease absorption
• ADRs photosensitivity, drug-induced lupus,
  serum sickness-like rxn, severe hypersensitivity
  syndrome rxn, pneumonitis, hepatotoxicity, GI
  upset, blue-gray pigmentation, pseudotumor
  cerebri
• Doxycycline
• 50 to 100mg BID
• Antacids dairy decrease absorption
• ADRs photosensitivity, GI upset, pseudotumor
  cerebri
• Erythromycin
• 250 to 500 mg BID
• ADRs GI upset

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Minocycline-induced cutaneous pigmentation
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Antiandrogenic Agents

• Decreases sebum production
• Clinical features suggesting a hormonal influence
  on acne
• Premenstrual flares
• Lesions primarily on lower face (jawline) chin
• Hirsutism or male-pattern alopecia
• i.e., Spironolactone

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Oral Contraceptives

• Suppresses androgen production ? decreases sebum
  production
• Look for OCPs w/ low-androgen progestin component
  (norethindrone, desogestrel, levonorgestrel)
• Takes 3-6 months may get slightly worse before
  it gets better.

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Combination Therapy

• Topical Abx benzoyl peroxide
• Topical retinoids topical Abx
• Topical retinoids PO Abx
• Topical retinoids (am) benzoyl peroxide (pm)
• Topical retinoids (am) benzoyl peroxide/topical
  Abx (pm)

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Isotretinoin (Accutane)

• For nodular/cystic acne
• Reduces sebum production
• Requires a 4 to 5 month course
• Side effects
• Arthralgia/stiffness
• Tendinitis
• Elevated serum lipids
• Teratogenic