ABSTRACT
Bismuth subnitrate is a highly water-soluble crystalline compound that has been used as a treatment for duodenal ulcers and anti-diarrheic agent. It is indicated for over-the-counter use as an antacid. In otolaryngology, it is used in bismuth iodoform paraffin paste for its adstringent and antiseptic properties. A 50-year-old man had a radical mastoidectomy right for chronic suppurative otitis media. Post-operatively, a bismuth and iodoform paraffin paste-impregnated gauze was packed into the external auditory canal, left in situ for 2 weeks and changed biweekly. Patch testing showed positive reactions to the bismuth iodoform paraffin pack, bismuth subnitrate, iodoform 5%, 10% and 25% pet. and to potassium iodide 25% pet. Twenty controls were negative to bismuth subnitrate and iodoform 10% and 25% pet.
