Core Dermatology Diagnoses / CategoriesInflammatory

Acne vulgaris

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Publish date: Posted on
Last updated: August 18, 2022

Keywords #

acne vulgaris
acne
comedones
pilosebaceous

Diagnosis #

Acne vulgaris is an inflammatory disorder of the pilosebaceous unit that occurs as a result of a hypersensitivity reaction to normal circulating levels of androgens and is aggravated by Cutibacterium acnes (formerly Propionibacterium acnes).[1] Diagnosis can be made clinically with severity determined by the number of noninflammatory comedones, inflammatory lesions (papules, pustules, nodules), and presence of scarring.

Many things contribute to the development of acne and may affect clinical features. Physical contributors such as oil-based cosmetics or mechanical coverings (i.e. chin straps, helmets) are common causes of acne and may present in the distribution of the area that was covered.[2] Hormonal fluctuations can also be a significant exacerbating factor, particularly in adult women.[2] Additionally, there is evidence that stress and diet play a role. Increased levels of stress and high-glycemic diets are most often associated with worsening of acne symptoms.[2,3] Several medications are known to contribute to acne vulgaris as well, including steroids, hormonal medications (such as oral contraceptives), isoniazid, epidermal growth factor inhibitors, and certain supplements.[2,4]

Key Concepts #
  • Inflammatory disorder of the pilosebaceous unit. The disease can be chronic but is often self-limiting.
  • One of the most common dermatologic complaints. Over 80% of teenagers are affected.
  • Can present with inflammatory and noninflammatory lesions, most commonly on the face, but may be on arms or trunk as well.
Epidemiology #

Acne vulgaris is present in over 80% of teenagers and persists beyond the age of 25 in 3% of men and 12% of women.[2] The disease may present as early as 8 years of age, and some women may develop acne for the first time after the age of 25. It has been estimated that 30% of teenagers have acne severe enough to require medical treatment.[2]

Clinical Features #
  • Acne vulgaris presents with a spectrum of severities. Depending on the severity, the disease can include comedones, papules, pustules, inflamed nodules, superficial pus–filled cysts, and deep inflamed sacs.
  • Mild acne is predominated by non-inflammatory comedones.
  • Moderate acne has an increased number of inflammatory papules, occasional nodules, and possibly mild scarring.
  • Severe acne is defined by widespread inflammatory lesions and nodules with scarring. It usually causes scarring (regardless of other characteristics) and may cause serious psychological distress.
  • Lesions are most common on the face, but the upper back, neck, and chest are also commonly affected.
Differential Diagnoses #
Diagnostic Workup #

Diagnosis can almost always be made by obtaining an adequate history and conducting a thorough skin exam.

Treatment #

Treatment depends on the severity of disease with increasing management required for more severe cases.

  • Mild: benzoyl peroxide wash, topical antibiotics, topical retinoids, sulfacetamide products, azelaic acid, dapsone gel
  • Clindamycin and erythromycin are the most commonly used topical antibiotics
  • Importantly, topical antibiotics must be used in combination with benzoyl peroxide to limit antibiotic resistance. Several combined topical formulations exist for this purpose including Benzaclin, Duac, or Acanya (benzoyl peroxide/clindamycin) and Benzamycin (benzoyl peroxide/erythromycin).
  • Topical retinoids include adapalene (Differin), tazarotene (Tazorac), and tretinoin (Retin-A)
  • Tretinoin is often the least expensive but is irritating and photolabile, meaning it is most stable when applied at night.
  • Adapalene is less irritating and photostable. It is now available over the counter as Differin Gel.
  • Tazarotene is initially irritating, but tolerance improves with continued use, also photostable.
  • Sodium sulfacetamide and azelaic acid are mildly anti-inflammatory and may improve symptoms in some. Both can cause dryness and irritation.
  • Dapsone gel has limited efficacy, but no systemic risks. However, patients should be counseled that topical application of dapsone gel followed by benzoyl peroxide may result in a temporary local yellow or orange discoloration of the skin and facial hair.
  • Moderate: same as above with the addition of oral antibiotics and/or hormonal therapy
  • Tetracyclines (doxycycline, minocycline) are the most commonly used oral antibiotics. Doxycycline is usually first-line treatment because of a more favorable side effect profile. Minocycline may cause pigmentary changes, pseudotumor cerebri, and drug-induced systemic lupus erythematosus. Both are associated with esophagitis and sun sensitivity and should not be used during pregnancy.
  • Several other oral antibiotics are also used including amoxicillin, cephalexin, and trimethoprim/sulfamethoxazole.
  • In females with hormonal acne, oral contraceptives may be helpful, and spironolactone may be used. Neither may be used in patients considering pregnancy.
  • Severe: same regimen as above, consider oral isotretinoin for refractory cases or those at risk for significant scarring
  • Isotretinoin is considered in moderate to severe cases due to some moderate side effects that has been well documented.[6]
  • The most common side effect is xerosis, but it may also cause hyperlipidemia, transaminitis, arthralgias, and myalgias.
  • Rarely may cause pseudotumor cerebri and depressive symptoms with increased risk of suicide., especially if a tetracycline derived antibiotic is continued.
  • Severely teratogenic and requires enrollment in iPledge, a risk management program mandated by the FDA.
  • Through this program, patients must list two forms of birth control and females are required to undergo monthly pregnancy tests.
  • Dosage of isotretinoin is typically started at 0.5 mg/kg/day for the first month and increased to 1.0 mg/kg/day as tolerated by the patient. While both dosages typically improve symptoms, 1.0 mg/kg/day dosing has been shown to decrease relapse rates.[7]
  • Similarly, a cumulative dose of >120 mg/kg has been shown to have a lower relapse rate, with the decrease in risk of relapse plateauing around 150 mg/kg cumulative dose.[7]
  • Others: Intralesional steroids may be used for persistent lesions in some cases.[5]

Treatment Regimen Examples

  1. Mild comedonal acne: Tretinoin 0.05% cream QHS, benzoyl peroxide 5% wash daily.
  2. Mild to moderate acne with both comedones and inflammatory lesions: tretinoin 0.05% cream QHS, clindamycin 1% solution QAM, benzoyl peroxide 5% wash daily. Add doxycycline 100mg daily with food for refractory symptoms.
  3. Adult female hormonal acne: adapalene 0.1% gel QHS, benzoyl peroxide 5% wash daily, spironolactone 100 mg daily (dosage may be between 50 and 200mg daily).
  4. Cystic acne with scarring: oral isotretinoin 0.5 mg/kg/day for the first month, with goal dose of 1.0 mg/kg/day until a cumulative dose of at least 120 mg/kg is reached. Adjust regimen as tolerated and monitor monthly through iPledge. Cosmetic procedures may be pursued for treatment of scarring.
Slide Viewer #
https://utahderm.med.utah.edu/image-viewer/?diagnosis=acne_vulgaris
References #
  1. Purdy, Sarah, and David de Berker. “Acne vulgaris.” BMJ clinical evidence 2011 (2011).
  2. Sutaria, Amita H., and Joel Schlessinger. “Acne vulgaris.” StatPearls [Internet]. StatPearls Publishing, 2018.
  3. Kucharska, Alicja, Agnieszka Szmurło, and Beata Sińska. “Significance of diet in treated and untreated acne vulgaris.” Advances in Dermatology and Allergology/Postȩpy Dermatologii i Alergologii 33.2 (2016): 81.
  4. Pontes, Thaís de Carvalho, et al. “Incidence of acne vulgaris in young adult users of protein-calorie supplements in the city of João Pessoa-PB.” Anais brasileiros de dermatologia 88.6 (2013): 907-912.
  5. Levy, Moise L., and Mark V. Dahl. “Treatment of acne vulgaris.” UpToDate [Internet] (2018).
  6. McLane, John. “Analysis of common side effects of isotretinoin.” Journal of the American Academy of Dermatology 45.5 (2001): S188-S194.
  7. Layton, A. M., et al. “Isotretinoin for acne vulgaris—10 years later; a safe and successful treatment.” British Journal of Dermatology 129.3 (1993): 292-296.
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