Learn about 7 skin diseases in which zinc supplements could be useful according to different scientific studies.
It is estimated that one third of the world population has a deficit in the intake of zinc, mainly in undeveloped countries. Zinc deficiency is associated with malnutrition and diseases that cause severe diarrhea. In advanced countries, the probability of having a zinc deficiency is lower and is associated with absorption deficit in the intestine, inadequate intake, pregnancy and lactation (1).
Zinc deficiency causes skin diseases such as pellagra or enteropathic acrodermatitis. On the other hand, zinc deficiency has been associated with some inflammatory skin diseases, such as atopic dermatitis, Bechet's disease or lichen planus (2).
Despite the strong link between zinc and the skin, little is known about its use as a treatment. The search for therapies anti-inflammatory and immunomodulatory has led to the study of the role of zinc supplements in the skin, which is what we are going to review in this text.
Mechanism of action and forms of supplementation
Zinc is a micronutrient, or essential trace element, that participates in enzymatic processes in the body, in protein structures, and regulates gene expression (3). acts in several mechanisms body's immune system, both in innate and adaptive immunity. Decrease the activity of neutrophils, helper T lymphocytes and the expression of inflammation receptors (Toll-Like) in keratinocytes (2).
Regarding the forms of supplementation, a regular intake of zinc in the diet is necessary, since the human body lacks storage systems. Zinc can be supplemented orally in both the sulfate/citrate form and the gluconate form. In the gluconate form, studies use 30 to 90 mg per day, and in the sulfate form, 0.2 to 0.6 grams per day. It can be supplemented in pills, capsules, jellies or gel (1,2).
Zinc supplements: 7 diseases in which they could be useful
1. Viral warts
It is the most widespread indication in dermatology, despite its controversial evidence. Common viral warts are caused by a small group of human papillomaviruses and lack specific antiviral treatment. Destructive methods such as keratolytic agents (“anti-warts”), cryotherapy (liquid nitrogen) or electrocautery are used to treat them.
Warts is the pathology in which oral zinc has been studied the most and there are contradictory studies, some find improvement compared to placebo, compared to others that find no differences (3). The addition of zinc supplements as a treatment for viral warts does not have adequate scientific support.
Compared with placebo, it shows improvement in acne lesions after 12 weeks of oral supplementation. Its effectiveness is less than that of antibiotics. When added to treatment with vitamin A, its effectiveness increases, which is fundamentally in reducing inflammatory lesions, papules, and pustules. It does not seem to have any effect on retentional acne lesions, in other words comedones or blackheads.
Interestingly, the most common side effect of zinc supplementation in healthy acne patients was nausea, abdominal pain, and vomiting, which in some cases required discontinuation of treatment (2).
3. Atopic dermatitis
Low levels of zinc have been found in the blood, hair and red blood cells in patients with atopic dermatitis. In spite of everything, these findings correspond to studies in few patients and were not related to greater severity in dermatitis (3).
There are two studies on the efficacy of adding zinc supplements to the basal treatment of patients with atopic dermatitis and another one compared with oral antihistamines. They were done in children. No differences were found in one of them and in another the severity and pruritus improved when adding oral zinc (2,4).
4. Diaper rash
In a study in 179 newborns it was found that 89 of them who were supplemented with zinc sulfate reduced the incidence of diaper rash (2).
5. Hidradenitis suppurativa
Studied in three studies, two of them without a control group and combined with other treatments. No improvement was found in the fistulas or in the pain, and in the patients who experienced improvement, a relapse was observed when oral zinc was discontinued. Despite finding clinical improvement in some patients, the study of inflammation markers in the skin of patients with hidradenitis suppurativa treated with zinc increased. Adding doubts to this clinical improvement (5).
The authors, in general, conclude that it may be a treatment to be developed, as a complementary non-pharmacological approach in this pathology that is sometimes difficult to control (6).
It is a fairly old study, it was found that patients with extensive plaque psoriasis supplemented with zinc increased its levels in the skin of the plaques and in the blood. Despite everything, no improvement was found in redness, scaling, and thickness in patients who took it versus those who did not (placebo) (7).
A study in 44 patients found a slight improvement with oral zinc treatment for rosacea, but this was not significant. Some patients even worsened and suffered gastrointestinal symptoms, which led to the premature termination of the study (8).
Zinc supplements to treat skin diseases: conclusions
Oral zinc supplementation may have a anti-inflammatory and immunomodulatory effect theoretically capable of improving some skin diseases.
In spite of everything, even when submitting studies in acne or hidradenitis suppurativa the results could be promising, the evidence for use in dermatology is little and contradictory.
1. Roohani N, Hurrell R, Kelishadi R, Schulin R. Zinc and its relevance to human health: an integrative review. J Res Med Sci 2013; 18: 144-157.
2. Dhaliwal S, Nguyen M, Notay M, et al. Effects of zinc supplementation in inflammatory skin diseases: a systematic review of clinical evidence. Am J Clinical Dermatology 2019 [Epub ahead of print]
3. Mahmoodi H, Ghodsi SZ, Tavakolpour S. Cryotherapy plus oral zinc sulfate versus cryotherapy plus placebo for treating common warts: a double-blind, randomized, placebo-controlled trial. Int J Dermatol for Women 2017: 20: 87-90.
4. Gray NA, Dhana A, Stein DJ, Khumalo NP. Zinc and atopic dermatitis: systematic review and meta-analysis. J Eur Acad Dermatol 2019; 33: 1042-1050.
5. Dreno B, Khammari A, Brocard A et al. Hidradenitis suppurativa: the role of impaired cutaneous innate immunity. Arch Dermatol 2012; 148: 182-186.
6. Hendricks A, Hirt P, Sekhon S, et al. Non-pharmacological approaches to hidradenitis suppurativa: a systematic review. J Dermatol Treatment 2019; 4: 1-8.
7. Voorhees J, Chakrabarti S, Botero F, et al. Zinc therapy and distribution of psoriasis. Arch Dermatol 1969; 100: 669-673.
8. Bamford JT, Gessert CT, Haller IV et al. Randomized, double-blind trial of zinc sulfate 220 mg twice daily for the treatment of rosacea. Int J Dermatol 2012; 51: 459-462.