Acne

Mark Lebwohl, M.D.
Mt. Sinai School of Medicine

Definition/Key Clinical Features
Differential Diagnosis
Best Tests
Best Therapy
Best References

Definition/Key Clinical Features

• Characteristic skin lesions
  • Open and closed comedones
  • Erythematous papules
  • Pustules
  • Nodules
  • Cysts
  • Scars
• Most commonly affects face but can involve back and chest
• Earlier onset and increased severity in males
• Premenstrual flares common in females

Major forms

Comedonal Acne

• Comedones
  • Keratinized cells
  • Sebum
• Predominance of open (blackheads) and closed (whiteheads) comedones

Inflammatory Acne

• Erythematous papules (3–10 mm)
  • Develop into pustules or resolve into fading erythematous macule
  • May cause postinflammatory hyperpigmentation
  • Pustules
  • Superficial, dry in a few days
• Nodules (≥ 1 cm)
  • Firm, erythematous, tender nodules becoming fluctuant or forming cysts
  • Fluctuant sinuses result in postinflammatory pigmentary changes and scarring

Clinical Variants

• Acne conglobata
  • Severe form with confluent large cysts, abscesses, and draining sinus tracts
• Acne cosmetica
  • Low-grade form resulting from use of greasy, occlusive cosmetics and lotions
• Acne excoriée
  • Large ulcers and erosions caused by picking of minor lesions
• Acne mechanica
  • From repeated trauma and rubbing (e.g., wearing sports helmets, shoulder pads, or bras)
• Pomade acne
  • Caused by thick oils in hair
• Neonatal and infantile acne
  • Erythematous papules and pustules lasting 2-6 mo after birth
  • May signal severe acne later in life

Differential Diagnosis

• Folliculitis
• Milia
• Perioral dermatitis
• Chloracne
• Hidradenitis suppurativa
• Favre-Racouchot disease
• Rosacea

Best Tests

• Diagnose by clinical features

Best Therapy

• Depends on acne type and severity

Topical Therapies

Comedonal Acne

• Topical retinoids to unplug follicles and allow topical antibiotic and benzoyl peroxide penetration.

Inflammatory Acne

• Treatment alternatives (by effectiveness)
  • Retinoids and benzoyl peroxide most effective
  • Topical antibiotics less effective but better tolerated.
    • Can be used in combination with benzoyl peroxide (clindamycin 1% and benzoyl peroxide 5%).
    • Common regimen: antibiotic–benzoyl peroxide in morning and topical retinoid in evening.
  • Azelaic acid
    • Can be used in combination with topical retinoids, benzoyl peroxide, or topical antibiotics.
  • Sulfur-resorcinol lotion
  • Effective drying and peeling agent for treating individual lesions.

Topical Drugs for Acne

Retinoids

• Most effective
• Adverse effects
  • Dryness
  • Irritation
  • Photosensitivity
• Adapalene
  • Dose: 0.1% gel q.d.
  • Cost/Mo: 15 g/$37.99
• Tazarotene
  • Dose: 0.05% or 0.1% gel q.d.
  • Cost/mo: 30 g/$75.99
• Tretinoin
  • Dose: 0.01%–0.05% preparations q.d.
  • Cost/mo: 20 g/$23.99

Benzoyl Peroxide

• Most effective
• Adverse effects
  • Dryness
  • Irritation
• Dose: 2.5%–10% preparations b.i.d.
• Cost/mo: 45 g/$13.99

Antibiotics

• Clindamycin
  • Adverse effects
    • Antibiotic resistance
  • Dose: 1% preparation b.i.d.
  • Cost/mo: 30 g/$18.99
• Erythromycin
  • Adverse effects
    • Antibiotic resistance
  • Dose: 2% preparation b.i.d.
  • Cost/mo: 30 g/$18.30
• Erythromycin–benzoyl peroxide
  • Adverse effects
    • Dryness
    • Irritation
    • Contact dermatitis
  • Dose: 3% erythromycin, 5% benzoyl peroxide gel b.i.d.
  • Cost/mo: 46.6 g/$102.99
• Sodium sulfacetamide-sulfur
  • Adverse effects
    • Dryness
    • Irritation
    • Contact dermatitis
  • Dose: 10% sodium sulfacetamide, 5% sulfur lotion b.i.d.
  • Cost/mo: 30 g/$21.99

Azelaic Acid

• Adverse effects
  • Stinging
  • Irritation
• Dose: 20% cream b.i.d.
• Cost/mo: 30 g /$45.99

Sulfur and Resorcinol

• Adverse effects
  • Dryness
  • Peeling
  • Contact dermatitis
• Dose: 2% resorcinol, 8% sulfur preparation q.d. or b.i.d.
• Cost/mo: 18 g/$4.49

Salicylic Acid

• Adverse effects
  • Dryness
  • Irritation
• Dose: 0.5%–2% preparations q.d. or b.i.d.
• Cost/mo: 21 g/$7.99

Systemic Therapies for Nodulocystic Acne or Inflammatory Acne Unresponsive to Topical Therapy

Antibiotics: First-line Therapy

• Doxycycline
  • Adverse effects
    • Photosensitivity
    • GI symptoms
    • Candidiasis
  • Dose: 50–100 mg p.o., b.i.d.
  • Cost/mo: $28.99
• Erythromycin
  • Adverse effects
    • GI symptoms
    • Candidiasis
  • Dose: 250-500 mg p.o., b.i.d.
  • Cost/mo: $17.98
• Minocycline
  • Adverse effects
    • GI symptoms
    • Candidiasis
    • Vertigo
    • Lupuslike syndrome (rare)
    • Hepatitis (rare)
  • Dose: 50 mg p.o., q.d. to 100 mg p.o., q.i.d.
  • Cost/mo: $13.99
• Isotretinoin
  • Most effective agent; long-lasting remissions or cures; not used as first-line therapy because of serious potential adverse effects (teratogenicity, hyperlipidemia, cheilitis, alopecia, pyogenic granulomas, dry eyes, epistaxis, pseudotumor cerebri [rare]); limit treatment to 4-6 months or refer.
  • Dose: 0.5–2 mg/kg/day in 2 divided doses
  • Cost/mo: $60
• Tetracycline
  • Adverse effects
    • Photosensitivity
    • GI symptoms
    • candidiasis
  • Dose: 250 mg p.o., q.d. to 500 mg p.o., q.i.d.; b.i.d. preferred
  • Cost/mo: $7.99
• Trimethoprim-sulfamethoxazole
  • Adverse effects
    • Bone marrow suppression
    • Drug eruption
  • Dose: 160 mg trimethoprim, 800 mg sulfamethoxazole b.i.d.
  • Cost/mo: $28.98
• Norgestimate-ethinyl estradiol
  • For women only; alternative to antibiotics and isotretinoin.
  • Adverse effects
    • Thromboembolic disorders
    • Fluid retention
    • Hypertension
    • Breakthrough bleeding
    • Breast swelling and tenderness
  • Dose: 0.18 mg norgestimate, 0.035 mg ethinyl estradiol p.o., q.d. for 21 days; repeat q. 4 wk
  • Cost/mo: $32.99

Other Therapies

• Consider referral for the following:
  • Specialized abrasion therapy
  • Injections
  • Surgery

Best References

Bershad, et al: Arch Dermatol 138:481, 2002

Hirsch, et al: Semin Cutan Med Surg 20:190, 2001

Leyden, et al: Cutis 67(6 suppl):17, 2001

Strauss, et al: J Am Acad Dermatol 45:187, 2001

July 2004