Ces dernières années, plusieurs publications ont rapporté des cas d’enfants ayant présenté des symptômes neurologiques et gastro-intestinaux suite à l’ingestion d’infusions d’anis étoilé. De telles préparations sont parfois conseillées en médecine populaire lors de coliques du nourrisson. Dans la plupart des cas, l’intoxication est due à la contamination de la badiane de Chine (Illicium verum) par l’anis étoilé du Japon (Illicium anisatum). Nous rapportons le cas d’un nourrisson de 2 mois amené aux urgences pour des épisodes répétés, spontanément résolutifs, de cyanose centrale avec tétanie des membres. L’examen neurologique était perturbé entre les épisodes mais il s’était amélioré progressivement durant les heures suivantes. Le reste de l’examen clinique, ainsi que le bilan biologique et l’électroencéphalogramme étaient normaux. L’ingestion d’anisatine, substance toxique contenue dans l’anis étoilé du Japon, et la contamination de la préparation de badiane de Chine par de l’anis étoilé du Japon ont pu être prouvées. L’évaluation des malaises du nourrisson devrait toujours tenir compte de la possibilité d’une intoxication. L’anis étoilé est généralement considéré comme une substance inoffensive. Toutefois, elle peut parfois être à l’origine d’intoxications sévères avec des symptômes neurologiques et gastro-intestinaux. Afin de prévenir de tels événements, non seulement les parents, mais également le personnel de vente et le personnel de santé, devraient être informés des effets secondaires potentiels liés à l’ingestion de badiane de Chine en trop haute concentration ou à sa contamination par l’anis étoilé du Japon. Un meilleur contrôle par les autorités sanitaires des préparations en vente est également nécessaire.

In previous years, several publications have reported cases of infants presenting neurological and gastrointestinal symptoms after ingestion of star anise tea. Such teas are sometimes given in various cultures for the treatment of infant colic pains. In most cases, the cause of intoxication was contamination of Chinese star anise (Illicium verum) by Japanese star anise (Illicium anisatum). Indeed, the toxicity of Illicium anisatum, also known as Shikimi, is caused by its content in potent neurotoxins (anisatin, neoanisatin, and pseudoanisatin), due to their activity as non-competitive antagonists of GABA receptors. The main reasons explaining the frequent contaminations are the strong macroscopic resemblance of the 2 substances, as well as the fact that the fruits are often sold partially broken or in ground form. Therefore, in most cases, chemical analysis is required to determine the possible adulterations.

A 2-month-old infant, in good general health, was brought to the emergency unit after 3 consecutive episodes of central cyanosis and tetany of the limbs with spontaneous recovery the same afternoon. The child was also very irritable, regurgitated a lot, and positioned himself in opisthotonos. Between these episodes, the neurological exam showed some perturbations (horizontal nystagmus and Bell’s phenomenon, hypertony of the extensor muscles, and mild hypotony of the axial flexor muscles) with slow improvement over the following hours. The remaining clinical exam, the laboratory work (complete blood count, renal, hepatic, and muscular tests, capillary blood gas, plasmatic amino acids, and urinary organic acids), and the electroencephalogram findings were all normal. In the course of a detailed interview, the parents reported having given 3 bottles to their child, each one containing 200mL of an infusion with 4 to 5 fruits of star anise, in the hours preceding the symptoms to relieve colic pains. The last seizure-like event took place approximately 8h after the last ingestion. We could prove the ingestion of anisatin, the toxic substance found in Japanese star anise, and the contamination of Chinese star anise by the Japanese species. Indeed, the anisatin analysis by liquid chromatography and mass spectroscopy (LC-MS) in a urine sample taken 22h after the last infusion ingestion showed trace amounts of the substance. In another urine sample taken 33h after ingestion, no anisatin could be detected. Furthermore, the analysis of the fruit sample gave an anisatin concentration of 7800μg/kg while the maximum tolerance value in Switzerland is 1000μg/kg.

The evaluation of ALTE in infants should always include the possibility of intoxication. Star anise is generally considered a harmless medicine. Nevertheless, it can sometimes cause a severe intoxication resulting in various neurological and gastrointestinal symptoms. To prevent such events, not only the parents, but also the care personnel and pharmacists must be informed about the possible adverse effects caused either by the overdose of Chinese star anise or by the eventual contamination of herbal teas with Japanese star anise. A better control of the substances by the health authorities is also necessary.