Oral zinc sulfate in the treatment of recalcitrant warts

Abstract

Background Cutaneous warts are benign papillomas of the skin caused by infection with human papillomavirus. The primary treatment methods of warts are physical destruction. However, these treatments are not suitable for patients with multiple lesions or with fear of pain and scarring. Therefore, immune-modifying agents might be a useful therapeutic alternative because they can be painlessly and easily administrated. Zinc is a trace element that is essential for the functioning of the immune system. It could counteract viral infections. Zinc sulfate is a promising therapy for the management of multiple warts. Aim The aim of this study was to determine the association of low serum zinc levels with persistent viral warts and to assess whether oral zinc sulfate was effective in treating persistent viral warts. Patients and methods This randomized case–control clinical trial was conducted on 40 patients. Eligible patients had five or more warts of at least 6-month duration resistant to one or more lines of treatment. Blood samples of all patients were taken to determine basic serum zinc level using spectrophotometry. Patients were randomly divided into two groups; each group consisted of 20 patients. Group I received oral zinc supplementation 10 mg/kg up to 600 mg maximum daily dose for 1 month. Group II did not receive any treatment. All of the patients were instructed not to take any other treatment during the trial. At the end of the study, the patients were assessed and the serum zinc level was remeasured. The percent of improvement of the warts was classified as follows: excellent, greater than 75%; moderate, 75–50%; mild, less than 50%; and no change. Results At the beginning of the study, the mean serum zinc level in group I was 85.95 μg/dl and that in group II was 81.30 μg/dl. However, at the end of the study, the mean serum zinc level in group I was 115.61±19.69 μg/dl and that in group II was 81.90±36.04 μg/dl. Serum zinc level significantly increased after treatment compared with that before treatment in group I (P=0.013); moreover, it became significantly higher than that in group II (P=0.006). The significant increase in serum zinc level in group I was associated with more clinical improvement in the warts. Shorter duration of the disease was associated with better response. Patients with excellent improvement had significantly higher serum zinc level than those with no improvement. Conclusion Our findings suggest that oral zinc supplementation should be considered as a therapeutic option in the treatment of recalcitrant multiple warts. Zinc deficiency is relatively common in our population. Oral zinc supplementation was associated with elevation of serum zinc level, which was associated with clinical improvement in the warts.