Hydrogen cyanamide exposure: a case series from Pavia Poison Control Centre

Background Hydrogen cyanamide is a plant growth regulator introduced in Italy as Dormex in 2000, but recalled from the market in 2008. It's currently not authorized in Europe. Inhalation/dermal contact may cause irritation/caustic burns, ingestion of severe organ damage and concomitant alcohol consumption disulfiram-like reaction due to aldehyde-dehydrogenase inhibition by hydrogen cyanamide.Aims To study all exposure cases referred to our centre, evaluating temporal and geographic distribution and analysing clinical manifestations, including the ones after alcohol consumption.Methods We retrospectively evaluated all hydrogen cyanamide exposures referred to our Poison Control Centre (January 2007-December 2021). For each case, age, sex, exposure route/year, geographical location, intent of exposure, alcohol co-ingestion, emergency department-admission Poison Severity Score, signs/symptoms and treatment were analysed.Results Thirty subjects were included. Median case/year was 1 [1; 2]: 79% occurred after market withdrawal, 92% in Sicily. All exposures were unintentional and work related; 41% of patients also co-ingested alcohol. Mean poison severity score at emergency department admission was 1.54, more severe when ingestion occurred. The most common signs/symptoms were flushing, secondary to peripheral vasodilation (41%), hyperaemia/erythema (29%), dyspnoea (25%), nausea (20%), vomiting (12%), oedema (12%), II-III degrees burns (12%) and pharyngodynia (12%). All patients were treated symptomatically and fully recovered.Conclusions Hydrogen cyanamide exposure can lead to severe clinical manifestations. Despite its withdrawal from the Italian market, hydrogen cyanamide is still used: through PCC's crucial role in monitoring exposure to agricultural products efforts should be made to contrast illegal trade and increase awareness of its potential toxicity in those countries in which it's still legal. Hydrogen cyanamide is a plant growth regulator recalled from the market of many countries because of its potential toxicity. Few data describing hydrogen cyanamide toxicity exist in literature; our study describes hydrogen cyanamide exposures before and after Italian market withdrawal, focusing on clinical manifestations and route of exposure. We also describe symptoms arising from concomitant hydrogen cyanamide use and alcohol consumption due to hydrogen cyanamide ability to cause disulfiram-like reactions by inhibition of aldehyde dehydrogenase.