July 2014
Mrinal Gupta, Vikram K. Mahajan, Karaninder S. Mehta, and Pushpinder S. Chauhan
Abstract
Zinc, both in elemental or in its salt forms, has been used as a therapeutic modality for centuries. Topical preparations like zinc oxide, calamine, or zinc pyrithione have been in use as photoprotecting, soothing agents or as active ingredient of antidandruff shampoos.
Its use has expanded manifold over the years for a number of dermatological conditions including infections (leishmaniasis, warts), inflammatory dermatoses (acne vulgaris, rosacea), pigmentary disorders (melasma), and neoplasias (basal cell carcinoma).
Although the role of oral zinc is well-established in human zinc deficiency syndromes including acrodermatitis enteropathica, it is only in recent years that importance of zinc as a micronutrient essential for infant growth and development has been recognized. The paper reviews various dermatological uses of zinc.
Comments
Zinc is an important micronutrient required for the normal function of skin. The daily allowance of elemental zinc in infants with zinc deficiency is usually 3 mg/d for first 6 months and 5 mg/d for second six months. Subsequently, zinc may be supplemented as 10 mg/d during 1–10 years, 15 mg/d for adolescents and adults, and 20–25 mg/d during pregnancy and lactation.
For therapeutic purpose zinc is administered orally or parenterally as zinc sulfate (22.5 mg of elemental zinc/100 mg), zinc acetate (30 mg elemental zinc/100 mg), or zinc oxide (80 mg elemental zinc/100 mg). The recommended doses for elemental zinc are 0.5–1 mg/kg/day in divided doses in children and 15–30 mg/day in adults.
Gastrointestinal upsets with bloody diarrhea may occur sometimes after ingestion of zinc sulfate beyond recommended doses. Therapeutically, zinc can be used, both topically and in systemic form, for a large number of dermatological disorders. Its efficacy in treating acne perhaps remains the most studied despite varied results.
However, it should not substitute the treatment with proven first line therapeutic modalities as most of the studies showing efficacy of zinc are small case series or have small sample size. Interestingly, systemic zinc as a therapeutic modality does not find much favor despite many dermatological conditions shown responding to it.
Perhaps more experimental and clinical evidence in the form of appropriately blinded randomized control trials and case-control studies for the treatment of various dermatoses is needed to determine the efficacy of this low cost mode of treatment and compare it with the established treatment modalities.
Only after adequate studies for its efficacy and safety, the treatment guidelines or recommendations for zinc therapy can be made. Nevertheless, it can best be used as an adjuvant to established treatment modalities.
