Best Dx/Best Rx: Acne

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 (e 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.

Back to top | Home Page

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

Back to top | Home Page

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

Back to top | Home Page

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

Back to top | Home Page