Oral Zinc Gluconate as Treatment for Recalcitrant Cutaneous Warts: A Randomized, Double-blind, Placebo-controlled Trial

Oral Zinc Gluconate as Treatment for Recalcitrant Cutaneous Warts: A Randomized, Double-blind, Placebo-controlled Trial

Up to one-third of common warts can remain recalcitrant, an occurrence that has been attributed to impaired cell-mediated immunity. At present, no guidelines exist for the management of recalcitrant cutaneous warts. Zinc, a well-established immunomodulatory agent, has shown promise in this regard. Previous studies documenting the efficacy of oral zinc used zinc sulfate given at a maximum dose of 600 mg/day, equivalent to 140 mg of elemental zinc, which is over three times the recommended upper limit of 40 mg of elemental zinc per day. This raises concerns over safety and tolerability. In the Philippines, oral zinc is more widely available in chelated forms such as zinc gluconate, which have the benefit of improved absorption compared to non-chelated compounds such as zinc sulfate. This study will seek to determine if zinc gluconate 300 mg/day, equivalent to 40 mg of elemental zinc, will be efficacious in treating recalcitrant cutaneous warts. This lowered dose may have the added benefits of increased safety, tolerability, and cost-effectiveness.

Inclusion Criteria:

1. Male or non-pregnant female
2. Age 19 years and older
3. With ≥ one (1) recalcitrant common, mosaic, palmar, plantar, or periungual wart/s
4. Consent given

Exclusion Criteria:

1. Current or history of mental illness
2. Current or history of malignancy
3. Severe immunodeficiency states
4. Pregnant or lactating
5. Documented adverse effects to oral or topical zinc exposure
6. Oral intake of zinc supplements in the past 12 months or less
7. Oral Intake of H2 antagonists in the past 4 weeks or less
8. Oral intake of immunosuppressives in the past 4 weeks or less
9. Concurrent usage of other treatment modalities
10. Current anogenital warts