Background

In addition to topical antibiotics and retinoids, keratolytic agents provide another option for the topical treatment of acne.  Keratolytic agents are available as both prescription medications (azelaic acid, glycolic acid) and in OTC formulations (salicylic acid, sulfur, benzoyl peroxide).  They work by breaking down the highly keratinized outer layer of the epidermis, which can help open up pores plugged at the surface.  In addition, they help remove older, damaged surface tissue and promote the generation new skin. Some of the keratolytic agents also have antibacterial properties.

Medications

Azelaic Acid (Aziderm, Azelex, Finacea, Skinoren)

Azelaic Acid (Skinoren) Molecule

A naturally occuring dicarboxylic acid, azelaic acid is a generally well tolerated treatment for mild to moderate acne.   in addition to being a keratolytic agent, it has antibacterial and anti-inflammatory activities that are also helpful in resolving acne. However, because the action of azelaic acid is primarily at the surface of the skin, it is less effective at resolving nodular, cystic and inflammatory acne.  It generally comes packaged as a 15-20% cream.

Glycolic Acid

Glycolic acid molecule

Glycolic acid is a member of the increasing popular family of alpha-hydroxy acids (AHA).  Alpha-hydroxy acids are used extensively in the cosmetics industry as chemical peels designed to fight wrinkles and even out skin tone.  Like other keratolytic agents, glycolic acid acts by helping to remove the outermost layer of the epideris, removing damaged tissue and promoting new growth.  In acne treatment, it is primarily used to diminsh the appearance of acne scarsand even out skin tone, but can also be used as a general keratolytic agent to treat mild cases of acne.

Related Articles from The Science of Acne

What is Acne Vulgaris?
What Causes Acne?
Prescription Medications and Acne Vulgaris
Naturopathic Medicine and Acne Vulgaris
Light and Laser Therapies and Acne Vulgaris
Over the Counter Medications (OTC) and Acne Vulgaris

References and Sources

Books

PDR Staff Writers. 2011. 2011 Physicians’ Desk Reference (PDR)
Habif. 2009. Clinical Dermatology
Goodheart. 2006. Acne For Dummies

Online Resources

Keratolytic Agents @ Wikipedia
Acne Vulgaris @ Wikipedia
Acne Vulgaris @ eMedicine
Acne Treatment Reviews @ WebMD
Acne Treatment Reviews @ Acne.org

Scientific Research Articles

Iraji, et al. 2007. Efficacy of topical azelaic acid gel in the treatment of mild-moderate acne vulgaris.
Pazoki-Toroudi, et al. 2011. Combination of azelaic acid 5% and erythromycin 2% in the treatment of acne vulgaris.
Sagransky, et al. 2009. Benzoyl peroxide: a review of its current use in the treatment of acne vulgaris.
Garg, et al. 2009. Glycolic Acid Peels Versus Salicylic–Mandelic Acid Peels in Active Acne Vulgaris and Post‐Acne Scarring and Hyperpigmentation: A Comparative Study.
Kessler, et al. 2008. Comparison of α‐and β‐Hydroxy Acid Chemical Peels in the Treatment of Mild to Moderately Severe Facial Acne Vulgaris.
Abels, et al. 2011. A 10% glycolic acid containing oil‐in‐water emulsion improves mild acne: a randomized double‐blind placebo‐controlled trial.
Mastrofrancesco, et al. 2010. Azelaic acid modulates the inflammatory response in normal human keratinocytes through PPARγ activation.
Williams, et al. 2011. Acne vulgaris.
Imahiyerobo-Ip, et al. 2011. Changing the topography of acne with topical medications.
Davis, et al. 2010. A review of acne in ethnic skin: Pathogenesis, clinical manifestations, and management strategies.
Sathish, et al. 2011. Acne and Its Treatment Options – A Review.
Ingram, et al. 2009. Management of acne vulgaris: an evidence-based update.
Schroeder, et al. 2012. Medications used for Acne vulgaris: Practice trends and the use of topical combination products.
Barratt, et al. 2008. Outcome measures in acne vulgaris: systematic review.
Patel, et al. 2010. The development of antimicrobial resistance due to the antibiotic treatment of acne vulgaris: a review.
Lee, et al. 2010.  Effectiveness of conventional, low-dose and intermittent oral isotretinoin in the treatment of acne: A randomized, controlled comparative study.
Strauss, et al. 2007.  Guidelines of care for acne vulgaris management.
Shah, et al. 2010. Acne in skin of color: practical approaches to treatment.