Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT PART 6-27: Acne Vulgaris + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ Almost universal in puberty; may begin in premenarchal girls; may present or persist into fourth or fifth decade Open and closed comedones are the hallmark Severity varies from purely 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 (Propionibacterium 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 +++ 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 Download Section PDF Listen +++ +++ 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 + Diagnosis Download Section PDF Listen +++ +++ Laboratory Tests ++ Culture in refractory cases + Treatment Download Section PDF Listen +++ +++ Medications +++ 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 +++ Papular or cystic inflammatory acne ++ Antibiotics are the mainstay, used topically or orally Mild acne The first choice of topical antibiotics is the combination of erythromycin or clindamycin with benzoyl peroxide topical gel Clindamycin (Cleocin T) lotion (least irritating), gel, or solution or topical erythromycin gel or solution may be used twice daily and benzoyl peroxide in the morning The addition of tretinoin 0.025% cream or 0.01% gel at night enhances efficacy Moderate acne Oral doxycycline (100 mg twice daily), minocycline (50–100 mg once or twice daily), trimethoprim-sulfamethoxazole (one double-strength tablet twice daily), or cephalosporin (cefadroxil or cephalexin 500 mg twice daily) May be used in combination with topical benzoyl peroxide to minimize development of antibiotic resistance May take 3 months or more for truncal acne to resolve with oral antibiotic treatment In general, discontinuing oral antibiotics immediately without adjunctive topical therapy results in prompt recurrence Topical retinoids are excellent for long-term maintenance following oral antibiotics Subantimicrobial dosing of doxycycline (40–50 mg orally daily) can be used in patients who require long-term systemic therapy Highly effective alternatives for women with treatment-resistant acne include Combination oral contraceptives Spironolactone, 50–200 mg orally daily In pregnancy, tetracycline, minocycline, and doxycycline are contraindicated, but certain oral erythromycins or cephalosporins may be used Severe cystic acne: Isotretinoin Should be used before significant scarring occurs or if symptoms are not promptly controlled by antibiotics Informed consent must be obtained before its use in all patients An oral dosage of 0.5–1.0 mg/kg/day for 20 weeks for a cumulative dose of at least 120 mg/kg is usually adequate Drug is teratogenic and absolutely contraindicated during pregnancy Patient must be registered in iPledge system Side effects Cheilitis, dry skin, and photosensitivity occur in most patients If headache occurs, consider pseudotumor cerebri Depression At higher dosages, elevation of cholesterol and triglycerides and a lowering of high-density lipoproteins can occur Minor elevations of liver biochemical tests and fasting blood sugar can occur Moderate to severe myalgias rarely necessitate decreasing the dosage or stopping the drug Before starting treatment with isotretinoin, measure serum cholesterol, triglycerides, and liver biochemical tests; repeat measurements after 4 weeks of therapy Severe cystic acne: Triamcinolone acetonide Dose: 2.5 mg/mL, 0.05 mL per lesion Often hastens the resolution of deeper papules and occasional cysts +++ Therapeutic Procedures ++ A low glycemic diet has been associated with improvement and lower incidence of acne In otherwise moderate acne, injection of triamcinolone acetonide (2.5 mg/mL, 0.05 mL per lesion) may hasten resolution of deeper papules and cysts Cosmetic improvement of scars may be achieved with surgical procedures + Outcome Download Section PDF Listen +++ +++ Complications ++ Cyst formation Pigmentary changes in pigmented patients Severe scarring Psychological problems +++ Prognosis ++ The disease flares intermittently in spite of treatment The condition may persist through adulthood and may lead to severe scarring if left untreated Antibiotics continue to improve skin for the first 3–6 months of use Relapse during treatment may suggest the emergence of resistant P acnes Remissions following systemic treatment with isotretinoin may be lasting in up to 60% of cases Relapses after isotretinoin usually occur within 3 years and require a second course in up to 20% of patients +++ Prevention ++ Educate patients not to manipulate lesions Avoid topical exposure to oils, cocoa butter, and greases +++ When to Refer ++ Failure to respond to standard regimens When the diagnosis is in question Fulminant scarring disease (acne fulminans) + References Download Section PDF Listen +++ + +Bienenfeld A et al. Oral antibacterial therapy for acne vulgaris: an evidence-based review. Am J Clin Dermatol. 2017 Aug;18(4):469–90. [PubMed: 28255924] + +Costa CS et al. Oral isotretinoin for acne. Cochrane Database Syst Rev. 2018 Nov 24;11:CD009435. [PubMed: 30484286] + +Zaenglein AL. Acne vulgaris. N Engl J Med. 2018 Oct 4;379(14):1343–52. [PubMed: 30281982]