Intranasal zinc and anosmia: the zinc-induced anosmia syndrome.
OBJECTIVE
Commercial preparations of intranasal zinc gluconate gel are marketed as a remedy for the common cold. However, intranasal zinc has been reported as a cause of anosmia in humans and animals. Seventeen patients presenting with anosmia after the use of intranasal zinc gluconate are described.


METHODS
The authors conducted a retrospective case series of patients presenting to a nasal dysfunction clinic and conducted complete history and physical examination on all patients, including nasal endoscopy. All patients underwent detailed odor threshold and identification testing.


RESULTS
Threshold and identification testing revealed impaired olfaction in all patients. Inflammatory and traumatic causes of anosmia were excluded based on history, physical examination, and imaging. All patients diagnosed with zinc-induced anosmia or hyposmia reported sniffing deeply when applying the gel. This was followed by an immediate sensation of burning lasting minutes to hours. Loss of sense of smell was then perceived within 48 hours. Seven of 17 patients never developed symptoms of an upper respiratory infection.


CONCLUSIONS
The zinc-induced anosmia syndrome, characterized by squirt, sniff, burn, and anosmia, occurs after the exposure of olfactory epithelium to zinc cation. It can be distinguished from postviral anosmia based on history.
Department of Surgery, Head and Neck Surgery and Continuing Medical Education, University of California, San Diego School of Medicine, VA San Diego Healthcare System, San Diego, CA 92103, USA.
Thomas H
TH
Alexander
Terence M
TM
Davidson
D000281:Administration, Intranasal; D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000008:administration & dosage / Q000009:adverse effects*; D003139:Common Cold / Q000188:drug therapy* / Q000517:prevention & control; D005260:Female; D005942:Gluconates / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D004366:Nonprescription Drugs / Q000009:adverse effects; D000857:Olfaction Disorders / Q000139:chemically induced*; D012189:Retrospective Studies
D000998:Antiviral Agents; D005942:Gluconates; D004366:Nonprescription Drugs; C030691:gluconic acid