Quick Evidence Synopsis

Date completed: June 12, 2015

Elsevier EBM Center contributors: Megan Sands-Lincoln, PhD, MPH, and David R. Goldmann, MD

What is the clinical question? What are the benefits and harms of selected nonpharmacologic dietary and topical therapies for acne vulgaris?

What does the evidence conclude?

Intervention	Quality of Evidence ^a	Balance Between Benefits and Harms ^b
Low glycemic load or ginger	Low	Unknown effectiveness
Topical aloe vera as a supplement to tretinoin	Low	Unknown effectiveness

a Quality of evidence scale (GRADE [Grading of Recommendations Assessment, Development, and Evaluation]): high, moderate, low, and very low. For more information on the GRADE rating system, see http://www.gradeworkinggroup.org/index.htm .

b The Guideline Elements Model: http://gem.med.yale.edu/default.htm .

What are the parameters of our search?

Population: adults with acne vulgaris
Setting: outpatient
Intervention: nonpharmacologic treatments, including low-glycemic-load diet and topical aloe vera
Comparator: placebo, higher glycemic load diet
Outcomes: lesion count, quality of life (QOL), harms

What is the basis for our conclusions?

Population: adults with acne vulgaris
Setting: outpatient
Intervention: low-glycemic-load diet

Comparator: high-glycemic-load diet ( Table 1 )

Table 1

Diets with high or low glycemic loads in adults with acne vulgaris

Outcomes	Assumed Risk ^a	Corresponding Risk ^a	Relative Effect (95% CI) NNT	Number of Participants (Studies)	Confidence in the Effect Estimates (GRADE)	Comments
Outcomes	High Glycemic Load (95% CI)	Low Glycemic Load (95% CI)	Relative Effect (95% CI) NNT	Number of Participants (Studies)	Confidence in the Effect Estimates (GRADE)	Comments
Change in noninflammatory lesion count at 12 weeks	1.15 lesions	−3.89 lesions (−10.07, 2.29)	—	75 (2 RCTs)	Low	No difference

Abbreviations: CI, confidence interval; GRADE, Grading of Recommendations Assessment, Development, and Evaluation; NNT, number needed to treat; RCT, randomized controlled trial.

a Illustrative comparative risks.

Population: adults with acne vulgaris
Setting: outpatient
Intervention: Zingiber officinale (ginger capsule)

Comparator: placebo, active comparator ( Table 2 )

Table 2

Ginger capsules to treat acne vulgaris in adults

Outcomes	Assumed Risk ^a	Corresponding Risk ^a	Relative Effect (95% CI)	Number of Participants (Studies)	Confidence in the Effect Estimates (GRADE)	Comments
Outcomes	Baseline	Intervention at 6-mo Follow-up	Relative Effect (95% CI)	Number of Participants (Studies)	Confidence in the Effect Estimates (GRADE)	Comments
Mean Acne-QOL Total Score (95% CI)	60.4 (54.1–66.7)	88.2 (84.2–92.2)	QOL increased by 27.8 units (33.4–22.1)	31 (1 open-label trial)	Very low	Favors intervention
Mean Lesion Count (95% CI)	120 (95.1–144.9)	57.7 (39.9–75.5)	Mean lesion reduction 48%	31 (1 open-label trial)	Very low	Favors intervention