Silver toxicity

Background

• Silver exposure is typically seen in workplace environments, herbal supplements, and other products
• Exposure is usually topical, but can also include inhalation, and ingestion
• Common work place environments include
  • Silver nitrate manufacturing
    • Used in manufacturing mirrors, inks, dyes, germicides, antiseptics, and analytical reagents
• Other possible sources of exposure
  • Acupuncture needles
  • Silver jewelry
  • Herbal supplements
  • Silver sulfadiazine

Clinical Features

• Typically occur as chronic exposure
• Skin discoloration (Argyria)
  • Permanent bluish-gray discoloration thought to be due to increased melanin production

Significant Toxicity

• Rare
• 50 mg IV is considered fatal
• Thought to be related to blockade of Na-K-ATPase
• Pulmonary Edema
• Hemorrhage
• Necrosis of bone marrow, liver, and kidneys

Differential Diagnosis

Heavy metal toxicity

• Aluminum toxicity
• Antimony toxicity
• Arsenic toxicity
• Barium toxicity
• Bismuth toxicity
• Cadmium toxicity
• Chromium toxicity
• Cobalt toxicity
• Copper toxicity
• Gold toxicity
• Iron toxicity
• Lead toxicity
• Lithium toxicity
• Manganese toxicity
• Mercury toxicity
• Nickel toxicity
• Phosphorus toxicity
• Platinum toxicity
• Selenium toxicity
• Silver toxicity
• Thallium toxicity
• Tin toxicity
• Zinc toxicity

Evaluation

• Usually a clinical diagnosis
• Serum and urine levels can be sent
  • Serum <1 µg/L (<9 nmol/L)
  • Urine (24 hour) <2 µg/L (<18 nmol/L)

Management

• Argyria
  • Topical hydroquinone 5%
  • Sunscreen to prevent further pigmentation
• Silver Ingestion
  • Supportive Care
• Silver salt ingestion
  • treat as caustic ingestion
• Burns from silver salt
  • treat as chemical burns

Disposition

• Discharge unless shows signs of systemic toxicity

References

Lai Becker M., Burns Ewald M. Silver. In: Goldfrank's Toxicologic Emergencies. 9th Ed. New York: McGraw-Hill; 2011: 1321-1325