A Double-Blind, Randomized Clinical Trial of 20% Alpha/Poly Hydroxy Acid Cream to Reduce Scaling of Lesions Associated With Moderate, Chronic Plaque Psoriasis
August 2013 | Volume 12 | Issue 8 | Original Article | 855 | Copyright © August 2013
Kristie L. Akamine MD,a Cheryl J. Gustafson MD,a Brad A. Yentzer MD,a Brenda L. Edison BA,d Barbara A. Green RPh MS,d Scott A. Davis MA,a and Steven R. Feldman MD PhDa,b,c
aWake Forest School of Medicine, Center for Dermatology Research, Department of Dermatology, Winston-Salem, NC
bWake Forest School of Medicine, Center for Dermatology Research, Department of Pathology, Winston-Salem, NC
cPublic Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC
dNeoStrata Company, Inc, Princeton, NJ
BACKGROUND: Salicylic acid is a topical keratolytic agent used to reduce scaling and hyperkeratosis associated with psoriasis vulgaris. However, its use is limited due to potential systemic toxicity. Hydroxyacids also modulate keratinization and desquamation. Therefore, they may serve a beneficial role in the treatment of hyperkeratotic conditions. To date, there are no clinical studies in the literature regarding the efficacy of hydroxyacids for psoriasis treatment.
PURPOSE: To evaluate the therapeutic efficacy of topical 20% alpha-hydroxy/polyhydroxy acid versus standard salicylic acid to reduce scaling in patients with moderate, chronic psoriasis.
METHODS: Twenty-five subjects with moderate, chronic psoriasis were enrolled in a 2-week, double-blind, left-right, randomized, bilateral comparison clinical trial to compare the efficacy of 20% alpha-hydroxy/polyhydroxy acid emollient versus 6% salicylic acid cream and 24 were randomized/completed. Clinical evaluations to assess the severity of psoriasis and scaling were performed using a 6-point scale prior to treatment, as well as following 1 and 2 weeks of therapy.
RESULTS: Twenty-four participants completed the study. Both 20% alpha-hydroxy/polyhydroxy acid emollient and 6% salicylic acid cream were efficacious in reducing scale of psoriatic lesions. The topical 20% alpha-hydroxy/polyhydroxyacid reduced scaling at a faster rate; however, following 2 weeks of treatment the efficacy of both products were relatively the same.
CONCLUSION: 20% alpha-hydroxy/polyhydroxyacid is as efficacious as salicylic acid in regards to the de-scaling of psoriatic plaques. Additionally, 20% alpha-hydroxy/polyhydroxyacid cream may yield quicker results and less toxicity than salicylic acid. J Drugs Dermatol.
Psoriasis is a chronic, immune-mediated inflammatory skin disorder that affects 2-3% of Americans.1, 2 Plaque psoriasis is the most common form, accounting for 90% of psoriatic cases.2, 3 Classically, plaques are salmon-colored
with overlying, silvery-white, micaceous scale.2, 3 Psoriatic
lesions are often pruritic and/or painful. Although the majority of psoriatic cases are mild to moderate in severity, approximately 20% of patients suffer from moderate to severe
disease.1, 2 Severity of disease is determined by the percentage
of body surface area (BSA) involved, as well as by the overall degree of erythema, induration, and desquamation
within the psoriatic skin.4 In moderate to severe cases, the distribution of plaques can be quite extensive, resulting in severe disfigurement. Like many chronic diseases, there is no cure for psoriasis. Management often entails combination therapy, such as topical creams, systemic agents, and phototherapy,
with the main goals being to limit the development of new lesions and reduce symptoms.
Scaling is one of the most common symptoms reported by patients
with psoriasis.5 It results from epidermal hyperplasia, aberrant keratinocyte maturation, inflammation, and water loss in the stratum corneum.6, 7 A diversity of topical products, such as moisturizers and keratolytics, are used to help normalize the structure and function of the epidermis, thereby reducing pruritus
and scaling.6 Salicylic acid is a topical keratolytic agent with an exfoliative effect at concentrations of 5% and higher.8, 9 Salicylic
acid reduces scale by disrupting corneocyte cohesiveness, thereby promoting desquamation of corneocytes. This normalizes the thickness of the stratum corneum, ultimately improving the cosmetic appearance of psoriatic lesions.7, 8, 10 Although salicylic acid is efficient at reducing scaling, its use is limited by the risk of salicylate toxic effects, including: tinnitus, dizziness, metabolic acidosis,
CNS symptoms, and GI distress.6, 8, 11 Additionally, salicylic acid can inhibit calcipotriene and block the effects of phototherapy,thus reducing the efficacy of these other treatment modalities used for psoriasis.6, 8, 12