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For further information, see CMDT PART 6-27: Acne Vulgaris

Key Features

Essentials of Diagnosis

  • Occurs at puberty, though onset may be delayed into the third or fourth decade

  • Open and closed comedones are the hallmark of acne vulgaris

  • Severity varies from comedonal to papular or pustular inflammatory acne to cysts or nodules

  • Face, neck, and upper trunk may be affected

  • Scarring may be a sequela of the disease or picking and manipulating by the patient

General Considerations

  • The skin lesions parallel sebaceous activity

  • Pathogenic events include

    • Plugging of the infundibulum of the follicles

    • Retention of sebum

    • Overgrowth of the acne bacillus (Cutibacterium acnes) with resultant release of and irritation by accumulated fatty acids

    • Foreign body reaction to extrafollicular sebum

  • Hyperandrogenism may cause acne in women, accompanied by hirsutism or irregular menses


  • Acne vulgaris is more common and more severe in males

  • 12% of women and 3% of men over age 25 have acne vulgaris

Clinical Findings

Symptoms and Signs

  • Mild tenderness, pain, or itching

  • Lesions occur mainly over the face, neck, upper chest, back, and shoulders

  • Comedones are the hallmark

  • Closed comedones are tiny, flesh-colored, noninflamed superficial papules that give the skin a rough texture or appearance

  • Open comedones typically are a bit larger and have black material in them

  • Inflammatory papules, pustules, ectatic pores, acne cysts, and scarring are also seen

  • Acne may have different presentations at different ages

Differential Diagnosis

  • Acne rosacea (face)

  • Bacterial folliculitis (face or trunk)

  • Tinea (face or trunk)

  • Topical corticosteroid use (face)

  • Perioral dermatitis (face)

  • Pseudofolliculitis barbae (ingrown beard hairs)

  • Miliaria (heat rash) (trunk)

  • Eosinophilic folliculitis (trunk)

  • Hyperandrogenic states in women


Laboratory Tests

  • Culture in refractory cases



Comedonal acne

  • Soaps play little part and, if any are used, they should be mild

  • Topical retinoids

    • Tretinoin

      • Very effective

      • Start with 0.025% cream (not gel) twice weekly at night

      • Increase frequency to nightly as tolerated

      • Pea-sized amount is sufficient to cover half of the entire face

      • Wait 20 min after washing to apply

    • If standard tretinoin preparations cause irritation, other options include

      • Adapalene gel 0.1%

      • Reformulated tretinoin (Renova, Retin A Micro, Avita)

      • Tazarotene gel 0.05% or 0.1%

    • Lesions may flare in the first 4 weeks of tretinoin treatment

    • Retinoids should never be used during pregnancy

  • Benzoyl peroxide is available in many concentrations but 2.5% is as effective as 10% and less irritating

  • Benzoyl peroxide in combination with adapalene is available as a single formulation

  • Use of topical antibiotics has been demonstrated to decrease pustular and comedonal lesions

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