Fatal reactions and methaemoglobinaemia after silver nitrate irrigation of hydatid cyst

Background:  Hydatid cyst remains an important public health problem in endemic areas including Isfahan, Iran. The mainstay of treatment for hydatid disease is surgery. Surgical approaches depend on the location, size and complications of the cyst. To prevent recurrence, inactivation of the scolex with scolicides prior to opening or removing the cyst is strongly recommended. Silver nitrate has been a common scolicidal agent in hydatid surgery for many years. Methaemoglobinaemia and morbid reactions are rare complications in individuals exposed to silver nitrate.