I. What is Beta-Hydroxy Acid (BHA, Salicylic Acid)?

Salicylic acid is the only member of the Beta-Hydroxy acid group. Salicylic acid and its salts exist on plants such as Wintergreen and Willow. Salicylic acid is commonly used as an antifungal agent. The reaction of acetic acid and salicylic acid produces aspirin (acetylsalicylic acid) which is an anti-inflammatory drug. Aspirin can be used to exfoliate the skin instead of salicylic acid. An aspirin mask can be made by crushing aspirin tablets and mixing it with distilled water.

II. How does Beta-Hydroxy Acid works (BHA, Salicylic Acid) on acne?

It has the same mechanism as alpha-hydroxy acid which is basically encouraging the removal of old skin cells and exposure of the newer, younger skin cells below. Beta-Hydroxy Acid (Salicylic Acid) is lipid soluble which means that they can penetrate oily skin. Salicylic acid also normalizes the excessive shedding of the cells inside the follicles which prevents pore clogging. For acneic skin, beta-hydroxy acid is superior compared to alpha-hydroxy acid because of its ability to breakdown blackheads and whiteheads.

Advantages

It can penetrate oily skin and thus it is a better choice for breakouts, blackheads, whiteheads, and oily skin.
Salicylic acid has anti-inflammatory properties and it reduces the irritation associated when applying hydroxy acids on the skin.

Disadvantages

It can cause deep burns at higher concentrations or long exposure times.
Once you stop using them, your skin returns to its original condition. AHA and BHA do not produce long lasting results and should be used regularly.
If high amounts of salicylic is absorbed through the skin, the user might experience what is known as salicylate toxicity. Symptoms of salicylate toxicity includes heavy breathing, dizziness, hearing impairment, lethargy, nausea and digestive disorders.

Efficacy

Beta-Hydroxy Acid works best at concentrations of 1% to 2% with an acidity level of pH 3. As the pH increases or their acidity decreases, the effectivity of beta-hydroxy acids decline.
( Source: Cosmetic Dermatology, October 2001, pages 15–18).

"Both inflammatory and non-inflammatory acne lesion counts were decreased in proportion to the duration of treatment. The side effects were tolerable in most cases, and all patients were pleased with their peel results. Stratum corneum hydration, skin surface lipid, skin pH, and transepidermal water loss were unchanged from baseline levels."
( Source: Ho-Sup Lee MD, Il-Hwan Kim MD (2003) Salicylic Acid Peels for the Treatment of Acne Vulgaris in Asian Patients Dermatologic Surgery 29 (12), 1196–1199.)

III. Forms, Dosage and Administration

Topical lotion, creams and gels. Concentration ranges from 0.5% up to 3%.

IV. Precautions

Avoid products with high alcohol content and other products with peeling agents. Pregnant women should avoid salicylic acid.
Avoid contact with eyes and other mucous membranes, such near the mouth or inside the nose.
This product should not be used on irritated skin or on any area of skin that is infected.

V. Side Effects

Itching, redness, swelling, may cause sun sensitivity. Product may produce stinging or burning sensation after initial application

Brand Names

Diprosalic®,Duofilm®,Coco-Scalp®,Neutrogena®

References

Desai A, Moy LS. The role of -hydroxy acids in the treatment of photoaging. Photoaging. Marcel Dekker, 2004: 117-140.
http://www.mayoclinic.com/health/drug-information/DR601247 ( updated 2007)
SALICYLIC ACID - A Plant Hormone Hayat, S.; Ahmad, A. (Eds.) 2007, XV, 401 p., Hardcover ISBN: 978-1-4020-5183-8
http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a607072.html (Last Revised - 11/01/2007 American Society of Health-System Pharmacists, Inc. Disclaimer )

Page last modified: January 07, 2008