Background: This paper presents a peculiar first case of an allergy to Silybum marianum (milk thistle) and Eragrostis tef (teff). Both teff and milk thistle have been presented in the literature (both domestic and foreign) in a positive light, the former as a new part of gluten-free diet, and the latter as a treatment for a number of conditions, particularly those of the liver.

Case presentation: A 29-year-old male presented at our clinic due to an episode of itching and burning in his mouth, swollen tongue, and difficulty swallowing following ingestion of teff flakes. He also reported sneezing, runny nose, watering and burning eyes, and wheezing following inhalation exposure to ground milk thistle. The patient's occupation is associated with exposure to these allergens. The patient underwent comprehensive allergy diagnostic assessments (including skin-prick testing, serum specific IgE levels, Faber test, spirometry, and acoustic rhinometry) and gastroenterological assessments. The diagnosis was established on skin tests with native allergens (milk thistle 16/35, teff flour 22/60, negative control 0/0, histamine 3/5) provided by the patient. There are no commercially available (standardized) tests for milk thistle or teff either in Poland or anywhere else in the world.

Conclusions: Milk thistle is available in the form of dry, finely-ground preparations (which are used as additives to bread, soups, and yoghurts) and extracts (which are used as ingredients in over-the-counter herbal remedies). Teff is a gluten-free cereal whose grains are rich in methionine, calcium, iron, folic acid, and antioxidants. This case report presents milk thistle and teff as potentially new allergens. A literature review revealed no similar allergy cases in Poland or elsewhere in the world.