Peripheral polyneuropathy due to chronic use of topical ammoniated mercury.

Despite their potentially disastrous side effects, topical mercury salts can still be found as ingredients in some over-the-counter preparations or local remedies. Peripheral polyneuropathy as a result of chronic ammoniated mercury poisoning was studied and followed over 2 years. A 36-year-old man developed peripheral polyneuropathy following chronic perianal use of an ammoniated mercury ointment. Highly elevated blood and urine mercury levels were found. Sural nerve biopsy showed mixed axonal degeneration-demyelination. There was progressive improvement of his symptoms over 2 years but neurophysiological examination revealed incomplete recovery. The availability of safer drugs should result in a complete ban of these dangerous compounds.