Hong Kong health officials on Friday reported a case of silver poisoning with a history of consumption of colloidal silver prescribed by a general practitioner.
This has prompted them to appeal to the public not to consume orally or parenterally any product that contains colloidal silver and to seek medical consultation immediately if they feel unwell after consumption, in particular if discoloration of the skin is developed.
The case involved a 47-year-old male patient who presented with unsteady gait and sensory loss over extremities in 2018 with a history of consumption of colloidal silver during the period from 2016 to 2018 as prescribed by Dr Leung Sik-chiu at his clinic in Wan Chai. The patient was diagnosed by the Health Authority to be a silver poisoning case.
Initial investigation revealed that the doctor had prescribed oral colloidal silver to this patient. Upon enquiries, the doctor indicated that he had also prescribed colloidal silver to other patients in the past year.
Silver has no known function in the human body and is not an essential nutrient. Chronic exposure to colloidal silver can cause argyria, which is the permanent bluish-grey discoloration of the skin. Systemic manifestations including anemia, bone marrow suppression, liver function derangement and neurological deficit can ensue.
In Hong Kong, there is no registered pharmaceutical product that contains colloidal silver as an active ingredient. There is no scientific evidence that supports non-topical (internal) use of colloidal silver for treating any specific disease or condition.