Acne Vulgaris

KEY FEATURES

Essentials of Diagnosis

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

• 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 of picking at and manipulating lesions 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 may be exacerbated by androgenic supplements or masculinizing hormone therapy in transgender individuals

Demographics

• 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)

• Dermatophytic infection (facial fungus) or demodex infection (face mites)

• Topical corticosteroid use (face)

• Perioral dermatitis (face)

• Pseudofolliculitis barbae (ingrown beard hairs)

• Miliaria (heat rash) (trunk)

• Eosinophilic folliculitis (trunk)

• Hyperandrogenic states in women

DIAGNOSIS

Laboratory Tests

• Culture in refractory cases

TREATMENT

Medications

Comedonal acne

• Hygiene plays little role in treatment; mild soaps are recommended

• 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 ...