High silver concentrations in biological samples following different exposures: Two case reports

Abstract : Background: Silver is used in various industrial applications, but also in confectioneries and for therapeutic use due to its antibiotic properties. Its toxicity is not well documented and most often only in the context of professional exposure. Aim: Here we report two cases of high silver concentrations in biological samples in two women: the first patient presented grey marks around her cuticles, probably due to her consumption of silvered sweets and the second patient presented agranulocytosis and thrombocytopenia occurring within 24 h after the topical application of a cream containing sulfadiazine and silver to burns over a large surface area. Methods: Silver concentrations were determined in blood and urine samples and sweets using inductively coupled plasma- mass spectrometry (ICP-MS). Results: The silver concentrations were elevated compared to population reference values and confirmed the hypotheses for the patients: the significant consumption of sweets coated with silver nanoparticles and the topical application of a cream containing silver to burns over a large area. Discussion-conclusion: After initial questioning by the dermatologist, Patient 1 explained that she consumed more than 30 bags of the sweets per year. She decreased her consumption of the sweets and the control performed one year later showed a plasma silver concentration of 1.5 μg/L. For Patient 2, the absorption of silver through burns over a large area appeared relatively significant, whereas it is very low through undamaged skin. The haematological cells counts returned to normal levels quickly and no other major effects were highlighted. To apply these findings to a larger population, further investigation to determine sulfadiazine and silver concentrations in plasma and urine have been initiated in a cohort of patients with burns over a large area.