Emerging mycotoxic syndromes in France: Epidemiological trends and public health implications (2015-2022)

Mushroom poisoning is a common cause of toxic exposure, and several "new mycotoxic syndromes" have been recognized since the 1990s. We conducted a retrospective multicenter study using the French Poison Control Centers cases database to describe their epidemiology in mainland France between 2015 and 2022. Cases involving species known to cause one of the seven « new » syndromes were included. Overall, 275 cases were identified, accounting for 1.7 % of the 2000 mushroom poisonings reported annually. Four syndromes were observed: neurotoxic morel syndrome (n = 159, 57.8 %), flagellate dermatitis (n = 110, 40.0 %), Amanita proxima/smithiana poisoning (n = 4, 1.5 %), and rhabdomyolysis (n = 2, 0.7 %). Most cases were mild (78.2 %), with 21 % moderate and 0.7 % severe. No cases of acromelalgic syndrome, Hapalopilus nidulans encephalopathy, or convulsive encephalopathy were recorded. Clinical features matched prior descriptions, with atypical presentations documented, including rare ocular sequelae after A. proxima ingestion and unusual neurological signs in morel poisoning. A pronounced April peak (42.2 %) coincided with morel season. Emerging mycotoxic syndromes remain infrequent but are increasing in relative frequency, driven mainly by morel-related neurotoxicity and shiitake dermatitis. Findings support strengthened toxicovigilance and clear public guidance: correct cooking of morels/shiitake, caution against confusion with toxic look-alikes, and expert identification when in doubt. Beyond France, countries with strong foraging traditions may face similar risks and should adapt surveillance and prevention accordingly.