Zinc supplementation may be a potential adjunctive approach for several major inflammatory skin diseases, including acne vulgaris and atopic dermatitis, yet clinical evidence of the benefit of zinc in these disorders is mixed. This is according to data from preliminary findings from small studies published in the American Journal of Clinical Dermatology.
The study was a systematic review of trials that evaluated zinc supplementation and associated disease-related outcomes in patients with acne vulgaris, atopic dermatitis, diaper dermatitis, hidradenitis suppurativa, psoriasis, and rosacea. In the review, a total of 22 studies, which included 1667 patients and evaluated zinc gluconate (10-90 mg/day), zinc sulfate (0.375-1.8 g/day), and zinc oxide (0.012 g/day), were included.
In the 9 studies that compared zinc with placebo in patients with acne, there was an overall trend in favor of zinc supplementation. Although another study found zinc supplementation plus lactoferrin and vitamin E was associated with significant reductions in comedones and inflammatory lesions, researchers were unable to determine whether the causative factor was the zinc alone, or the combination of the zinc with lactoferrin and vitamin E. Compared with zinc, antibiotics demonstrated superior efficacy for acne management in 3 studies.
Findings varied in 2 studies that evaluated oral zinc for atopic dermatitis, with 1 study showing no beneficial effect vs placebo, and the other study showing a potential benefit of zinc for reducing disease severity. In another study of patients with rosacea, no significant difference was observed between oral zinc sulfate and placebo. This study resulted in early termination, as zinc was found to be less efficacious than placebo.
Limitations of the studies included in this review included the small sample sizes and the use of placebos containing ingredients that may lead to worsening of acne.
Although zinc appears to possess anti-inflammatory properties that may theoretically result in clinical improvements in some dermatologic conditions, the investigators noted that zinc supplementation “may not be universally beneficial in dermatologic inflammatory disease.”
Dhaliwal S, Nguyen M, Vaughn AR, Notay M, Chambers CJ, Sivamani RK. Effects of zinc supplementation on inflammatory skin diseases: a systematic review of the clinical evidence [published online November 19, 2019]. Am J Clin Dermatol. doi:10.1007/s40257-019-00484-0