A well known and respected microbiologist (who also happens to have had Lyme disease) is Tom Grier. He has written extensively on Lyme and its miseries, and he lays out the scientific and medical aspects of colloidal silver use against Lyme.
Here's the bottom line: "colloidal silver is at best worthless, and at worst capable of causing permanent skin discoloration"
To find this article, search online for:
-- real concerns about colloidal silver grier --