L. Kircik, MD
Department of Dermatology, Indiana University School of Medicine, Indianapolis, IN
Acne vulgaris is a disorder of the pilosebaceous units located on the face, chest, and back. It affects up to 45 million Americans, mostly in the 15–24 year age group, and can cause a
poor self image, withdrawal, and even depression and suicidal ideation. More than $100 million per year is spent on OTC acne products. Scarring and postinflammatory hyperpigmentation are the most important sequelae.
Pathophysiology of Acne Vulgaris
The microcomedone is the precursor of all lesions.
Classification of Acne
a. Open comedones and closed comedones
b. Treated with topical agents
a. Papules: erythematous small bumps less than 1.0cm
b. Pustules: pus filled erythematous small bumps less than 1.0cm
c. May not respond to topical agents alone. Topicals can be combined with oral agents.
- Nodulocystic Acne
a. Nodules (more than 1.0 cm tender lesions)
b. Cysts (more than 1.0 cm tender lesions)
c. Treated with oral agents
The most important treatment goal is to minimize scarring by preventing further acne development. Patient compliance is also very important in acne treatment. Minimizing adverse events and ease of treatment will maximize patient compliance.
- Tretinoin (Retin-A®, Retin-A® Micro and Stieva-A®)
- Tazarotene (Tazorac®)
- Adapalene (Differin®)
Topical retinoids are most efficacious at preventing microcomedone formation. They should be applied sparingly to all affected areas, usually at night. Irritation and dryness make topical retinoid application challenging. It is advisable to avoid nasolabial and melolabial folds. Some retinoids, such as tazarotene, can be used as a short-contact treatment to avoid irritation. Use of gentle cleansers, noncomedogenic moisturizers, and avoidance of alcohol-based products and astringents will help to increase the compliance.
- Erythromycin (Aknemycin®, ATS®)
- Clindamycin (Cleocin T®, Clindagel®, Evoclin® Foam)
Both agents have anti-inflammatory and anti-infective action; however, due to reports of bacterial resistance, use as monotherapy is not recommended. Combinations of different
agents (e.g., in combination products) should be the first-line treatment for inflammatory lesions.
- Topical Clindamycin 1% + 5% BPO in moisturizing base (Duac®)
- Topial Clindamycin 1% + 5% BPO (Benzaclin®)
- Topical Erthromycin 3% + 5% BPO (Benzamycin®)
These combination products will fight both inflammatory and noninflammatory lesions (comedones). They will also help to prevent bacterial resistance. They may result in fabric
Normalizes Keratinization or is Keratinolytic
Decreases P. Acne
- All patients with acne can benefit from topical therapy, except those receiving isotretinoin.
- Topical retinoids should be applied to the whole acne prone area. They should be thought of as preventing new lesions rather than treating those that have already formed.
- For inflammatory acne, it is reasonable to use a combination topical therapy early on, such as a BPO/antibiotic combination. One can be used in the morning and the other in the evening.
- An adequate response to treatment can be measured in a few months, not weeks.
- Systemic therapy can be used if response is still poor after at least 3 months.
Importance of Vehicle in Topical Treatment
The role of vehicle in topical acne treatment is also very important.
- Glycerin – humectant
- Dimethicone – occlusive emollient
Combining these two products contributes to barrier restoration and will reduce adverse events such as dryness, peeling and irritation. Therefore, products containing these vehicles may be more tolerable for patients, in particular if they develop irritation with topical retinoids. The use of combination products will prevent emergence of antibiotic resistance.
Removal of noninflammatory lesions with a comedone extractor is helpful, but time consuming.
A spray of liquid nitrogen in moderate amounts or the application of slushed dry ice can be considered in the treatment of acne vulgaris. Periodic glycolic or salicylic acid peels also have benefits.
The Number One Reason for the Failure of Acne Treatment is Compliance
Management of the patients’ expectations and compliance are crucial aspects of acne treatment. Disease chronicity and long-term treatment should be discussed at length during the initial consultation. A skin care regimen with gentle cleansers and moisturizers will ease these patients into their treatment program and increase compliance by decreasing dryness and irritation from topical medications.
As Dr. Kircik notes, the microbe P. acnes remains central to the etiology of inflammatory acne lesions. Elucidation of the entire genome of this commensal organism has led to new insights into pathogenesis and to a new understanding of why certain therapeutic interventions are successful.1 For example, the genome discloses that P. acnes is capable of producing glycocalyx material necessary to form a biofilm.
In turn, this explains the relative resistance of the putative causative bacterium to topical antibiotics when given as monotherapy. The addition of benzoyl peroxide, which disrupts the biofilm-rich microenvironment, allows better penetration of a concomitant antibiotic. Disruption of the biofilm also increases the local oxygen tension, thereby creating a less satisfactory situation for P. acnes, a commensal anaerobe.
Development of antimicrobial resistance when acne is treated with topical antibiotic monotherapy is a real phenomenon. Even more importantly, the genome discloses that P. acnes possesses the necessary intracellular mechanisms to pass on resistance to other bacteria.
A recent study demonstrated that this may, indeed, happen under normal clinical conditions.2
Thus, use of synergistic therapy (such as benzoyl peroxide along with antibiotic) is truly appropriate. A recent innovative therapy, the use of high intensity visible blue light, is also justified by the genome-directed synthesis and secretion by P. acnes of a photo-target (porphyrin).3,4
The treatment of acne may expand even further as modern technology, such as genetic sequencing, is brought to bear on this common and distressing disorder.
- Bruggemann H. Insights in the pathogenic potential of Propionibacterium acnes from its complete genome. Semin Cutan Med Surg. 2005 ;24:67-72.
- Levy RM, Huang EY, Roling D, Leyden JJ, Margolis DJ. Effect of antibiotics on the oropharyngeal flora in patients with acne. Arch Dermatol 2003;139:467-71
- Morton CA, Scholefield RD, Whitehurst C. Birch J. An open study to determine the efficacy of blue light in the treatment of mild to moderate acne. J Dermatol Treat 2005;16:219-23.
- Tremblay JF, Sire DJ, Lowe NJ, Moy RL. Light-emitting diode 415 nm in the treatment of inflammatory acne: an open-label, multicentric, pilot investigation. J Cosmet Laser Ther. 2006 8:31-3.