Lawrence S. Neinstein, M.D., F.A.C.P.
Professor of Pediatrics and Medicine
USC Keck School of Medicine
Executive Director
University Park Health Center
Associate Dean of Student Affairs



Medical Problems - Dermatology - Acne (B4)

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Acne is the most common skin condition occurring in adolescents. Acne can have a devastating effect on a teen's self-image.

It is useful to review the stages of acne, pathophysiology and approach to therapy.

Stages of acne: It is useful to review acne vulgaris in teens for a moment.

comedonal acne
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The above is the first stage of typical acne which is comedonal acne.

Almost 85% of teens will have some degrees of acne. The etiology of acne is secondary to changes that occur in the pilosebaceous units of the face, upper chest and upper back. The key components that lead to acne are:

  • Androgen-induced increased sebum production
    Stimulates both enlargement and increased activity of sebaceous glands on face, neck and upper trunk
  • Abnormal keratinization of sebaceous and follicular epithelium
    Leads to retention hyperkeratosis and microcomedo formation
  • Proliferation of Propionibacterium acnes
    Excessive sebum and anaerobic environment secondary to the plugged follicles result in colonization and proliferation of P.acnes
  • Inflammatory response
    The bacterial infection triggers immune and nonimmune inflammatory reactions secondary to lipases, chemotatic factors and complement pathways.

There are many ways to grade acne, although perhaps the most description and useful in communicating both the type of acne and the treatment would include the following descriptions:

  • comedonal versus papular versus papulopustular versus cystic
  • location of the acne
  • severity: mild, moderate or severe

Thus a teen might have mild comedonal acne on their cheeks or moderate papulopustular acne on their forehead, checks and chest. This gives one not only a good idea of the type of acne but based on the type of lesions and severity, the type of intervention.

Below is mild papulopustular acne

mild papulopustular acne
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Here below is more severe papulopustular acne.

more severe papulopustular acne
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Here, in contrast, is cystic acne.

cystic acne
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Treatment can be based on different actions and degree of severity

  • Reverse obstruction of follicle
    Comedonal acne involves follicular obstruction and so these compounds can be very useful including:
    (Retin-A, azealic acid, differin, benzoyl peroxide*)
  • Decrease bacterial proliferation and inflammation
    In inflammatory acne involving pustules and papules both benzoyl perioxide and antibiotics can be useful including:
    Benzoyl peroxide and topical and systemic antibiotics
  • Mediate hormones
    This includes oral contraceptives which can be very useful in adolescent females for acne
  • Mediate sebaceous gland hypertrophy
    This involves accutane and is reserved for more severe acne.

General considerations:

There are a few general considerations for teens with acne:

  • Do not downplay the significance of the problem to the teen.
  • Teens have often tried many medications they have either bought at a store or gotten from a friend.
  • Better for the clinician to understand a few drugs and use them well than utilizing many different drugs.
  • Make sure teen understands how to use medications and their side effects.
  • Never promise instant success and reinforce that improvement may take months and that topical agents may make acne look worse in first 3-4 weeks.
  • Treat according to severity thus using:
    • For mild comedonal acne : Non prescription or prescription acne preparations containing salicylic acid or benzoyl peroxide.
    • For moderate-to-severe comedonal acne: Addition of tretinoin, adapalene or tazarotene, at bedtime.
    • For mild inflammatory acne : Addition of a topical antibiotic or 3% benzoyl peroxide with 3% erythromycin gel
    • For unresponsive or moderate-to-severe inflammatory acne : Requires the addition of a systemic antibiotic.
    • For nodular or nodulocystic acne that does not respond to oral antibiotics: Should be with isotretinoin by an experienced practitioner.
    • Combined oral contraceptives in females may be very useful therapy in all of the above forms of acne.
  • Important to review misconceptions with teens and parents including the lack of evidence that cola and chocolate causes acne, that uncleanliness causes acne, that sexual activity or masturbation causes acne.

Few specifics on topicals

Benzoyl Peroxide

  • Has bacterocidal effect on P . acnes as well as mild comedolytic action
  • 2.5%-10% gels, lotions, creams, soaps and washes - gels better tolerated than alcohol
  • Best to gradually increase the concentration and start either once or day or even every other day in individuals with sensitive skin
  • Side effects include peeling/irritation, contact dermatitis, bleaching of hair and clothing


  • These normalize keratinization, increases cell turnover, increase the penetration of other topical agents and decrease horny cell adhesion
  • Comes as cream (0.025%,0.05%, and 0.1%), gel (.01% and .025%) and Retin-A Micro 0.1% gel and Liquid (.05%)
  • Cream is least irritating followed by gel
  • New tretinoins include: Gel microspheres (designed to improve tolerability), Polymer Creams (designed to enhance delivery and decrease irritation) and Adapalne (similar to retinoids but is more photostable and causes less irritation).

As mentioned topicals may cause acne and skin to become slightly more irritated before improvement occurs.

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At 3 weeks
at 3 weeks
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At 6 weeks
at 6 weeks
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Other treatments include

Topical antibiotics including:

  • Benzoyl Peroxide
  • Erythromycin - 2% solution or gel
  • Clindamycin - 1% lotion, solution, gel
  • Sulfur - Sulfacetamide products - lotions
  • Combinations with topical antibiotics and retinoids

Systemic antibiotics.

These are indicated when there is either poor response to topical agents or there is more severe acne. It is important to avoid the combination of both topical antibiotics and systemic antibiotics together as that can increase resistance.

  • Minocycline - 50-100 mg qd/bid
  • Doxycycline - 50-100 mg qd/bid
  • Tetracycline - 250-500 mg bid
  • Erythromycin - 250 mg bid-qid

Hormonal Therapy

This includes both combination oral contraceptives and low-dose spironolactone. These can both suppress endogenous androgen production and decrease free testosterone.

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Copyright (©) 2004-2013 Lawrence S. Neinstein, University of Southern California . All rights reserved. Republication or redistribution of the text, table, graphs and photos is expressly prohibited. The University of Southern California shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon.