Zinc salts in dermatology
Indications
- Acrodermatitis entropathica : 3 mg/kg/day of elemental zinc (50 mg elemental zinc per 220 mg zinc sulfate) lifelong.
- Acquired zinc deficiency : 0.5–1.0 mg/kg/day of elemental zinc for children and up to 15–30 mg elemental zinc per day for adults.
- Warts :10 mg/kg/day oral zinc sulphate for 2 months for recalcitrant warts to a maximum dose of 600 mg/day (side effects are common).
- Cutaneous leishmaniasis : Oral zinc sulphate in doses of 2.5, 5, and 10 mg/kg/day for 45 days.
- Acne vulgaris : zinc gluconate (200 mg/day).
- Rosacea : Oral zinc sulphate 100 mg thrice a day for 3 months.
- Hidradenitis suppurativa :Oral zinc gluconate 90 mg/day as maintenance therapy or in combination with other therapies.
- Behcet’s disease and oral aphthae : Oral zinc sulphate 100 mg/day or 300 mg/day PO for MC lesions.
- Recurrent aphthous stomatitis (RAS): Oral zinc sulfate 150 mg twice daily.
- Alopecia areata :5 mg/kg/day of oral zinc sulphate for 6 months.
- Uremic pruritus.
- Amicrobial pustulosis of the skin folds (oral zinc was effective in two cases).
- Wilson disease : zinc acetate has a role .
- Dissecting cellulitis: zinc sulphate, 135 mg three times a day.
- Necrolytic acral erythema : zinc sulfate 220 mg orally twice daily.
Dosage
- 1–2 mg/kg daily of elemental zinc in three divided doses.
- Daily intakes of dietary zinc, according to the US RDA, are:
- Infants and children up to 3 years: 2 – 3 mg (RDA).
- Children 4 to 8 years: 5 mg (RDA).
- Children 9 to 13 years: 8 mg (RDA).
- Males 14 to 18 years: 11 mg (RDA).
- Females 14 to 18 years: 9 mg (RDA).
- Pregnant females 19 years and older: 11 mg (RDA).
- Breastfeeding females: 12 -14 mg (RDA).
- Zinc sulfate injection: IV: Full term infants and children up to 5 years of age: 100 mcg zinc/kg/day.
Baseline Monitoring
- Serum zinc level : normal reference range for zinc is 70–150 mcg/dl (10.7–22.9 µmol/l).
- Alkaline phosphatase.
Follow Up Monitoring
- Morning fasting specimen.
- Full blood count.
- Serum copper level.
- Stool examination for occult blood.
Side effects
- Common
- Stomach upset.
- Nausea, vomiting.
- Metallic taste in the mouth.
- Other
- Dizziness, headache,drowsiness.
- Increased sweating .
- Loss of muscle coordination.
- Alcohol intolerance.
- Hallucinations.
- Anemia.
- With high doses
- lower HDL cholesterol and raise LDL.
Contraindications
- Inadequate amount of copper.
- Hypersensitvity.
Pregnancy &Lactation
- Zinc sulfate : pregnancy category C .
- Zinc gluconate has not been formally assigned to a pregnancy category by the FDA.
- Use with caution in pregnant and lactating women.
- Elemental zinc is known to be excreted into human milk and may lead to copper deficiency in the nursing infant.
Precautions
- If zinc sulfate causes stomach irritation, zinc citrate should be tried.
- Zinc should be taken with water or juice.
- If zinc causes stomach upset, it can be taken with meals.
- Zinc should not be taken at the same time as iron or calcium supplements.
- Long-term use of zinc (including zinc in a multivitamin) should be accompanied by copper.
- For every 15 mg of zinc include 1 mg of copper.
- Zinc gluconate has a favorable safety profile and can be administered to pregnant women.
| Form | Elemental Zinc % | Absorption | Best For | Notes |
|---|---|---|---|---|
| Zinc Picolinate | ~20% | ✅ Very good | General supplementation, acne, skin issues | Chelated form; well tolerated |
| Zinc Citrate | ~34% | ✅ Good | General use, better taste (in lozenges) | Often used in dental/lozenge form |
| Zinc Gluconate | ~14% | ✅ Moderate | Cold remedies, immune support | Often used in lozenges, fewer GI issues |
| Zinc Acetate | ~30% | ✅ Good | Reducing cold duration | Fast absorption, found in lozenges |
| Zinc Sulfate | ~23% | ⚠️ Lower | Prescription needs (e.g., Wilson’s disease) | May cause stomach upset |
| Zinc Oxide | ~80% | ❌ Poor | Topical use only (e.g., sunscreens, rash) | Not for oral use |
| Zinc Methionine | ~21% | ✅ Very good | Muscle recovery, antioxidant effects | Bound to amino acid, good bioavailability |
| Zinc Orotate | ~20% | ✅ Possibly good | Claims of better cellular delivery (less evidence) | Popular in alternative circles |
Drug Info
- The normal plasma zinc level is 70–110 µg/dL and in serum 80–120 µg/dL
- The highest tissue concentration (>500 μg/g dry weight) being in the prostate, seminal fluid, uveal tissue, and skin.
- The skin contains nearly 6% of total body zinc.
- The continuous external supply of zinc is important for metabolic needs, growth, and tissue repair.
- Available forms of zinc supplementation include zinc sulfate, zinc acetate, zinc gluconate, and zinc propionate.
- Dosage must be based on the amount of elemental zinc present in the preparation, which varies between compounds.
- Animal foods like meat, eggs, fish, and oysters are rich in zinc.
- Zinc sulfate(220 mg) contains approximately 55 mg of elemental zinc.
- People who are zinc deficient tend to be more susceptible to a variety of infections.
- Zinc deficiency leads to increased susceptibility to opportunistic infections in people with AIDS.
- Zinc therapy should be monitored periodically with morning fasting specimen, full blood count, serum copper level, and stool examination for occult blood.
Zinc Converter
Reference Values:
- Adult Men RDA: 11mg
- Adult Women RDA: 8mg
- Upper Limit: 40mg
Conversion Rates:
- Zinc Gluconate: 14.3% elemental zinc
- Zinc Sulfate: 23% elemental zinc