Poppy seed allergy and a new link to buckwheat in one person
What it found
A 17-year-old girl had a severe allergic reaction after eating poppy seed cake, and lab tests showed her immune system also reacted to buckwheat.
This was found in one person.
What they found
Studies in people
Severe reaction to ground seeds
Eating just 1 g of ground poppy seeds caused hives, itching, eye inflammation, and breathing trouble within minutes. Her blood markers for an allergic reaction rose threefold in 3 hours. Eating up to 10 g of whole, unground seeds caused no symptoms at all.
Other food allergies present
Skin tests and blood work showed strong allergic responses to sesame, hazelnut, brazil nut, pistachio, cashew, and almond. She had a history of mouth swelling and itching after eating sesame rolls for 10 years.
Studies in people and animals
Cross-reaction with buckwheat
Lab tests on the patient's blood serum showed that buckwheat proteins blocked her immune response to poppy seeds by about 60%. This means her body treats these two unrelated plants as similar allergens.
No reaction to opium proteins
The doctors checked if her poppy seed allergy meant she would react to opium latex or raw opium from the same plant. Lab tests on her blood serum showed no cross-reaction with either substance.
Other findings
Grinding matters for reactions
The authors note that crushing or grinding poppy seeds seems crucial for triggering severe reactions. Whole seeds used on bread rolls or in yoghurt may not release the allergens the same way ground seeds in cakes do.
What the authors conclude
- They conclude that how poppy seeds are prepared, especially whether they are ground, strongly affects allergic reactions.
- They advise that people with poppy seed allergy should also be checked for buckwheat sensitivity, since their tests revealed a new cross-reaction between these two unrelated plants.
- The authors recommend strict avoidance of poppy seeds for anyone diagnosed with this allergy.
How it was done
Allergic reactions to poppy seeds are rare but can be very severe when they happen. The doctors wanted to find out exactly what caused this patient's reaction and whether other foods might trigger it too.
Doctors examined one 17-year-old girl who had a severe allergic reaction after eating a single bite of poppy seed cake. They did skin prick tests, blood tests, and fed her small amounts of poppy seeds under medical supervision. They also tested her blood serum against buckwheat and opium proteins in the lab.
What it can’t tell you
- This report describes only one person, so scientists do not yet know how common this buckwheat cross-reaction is among others with poppy seed allergy.
- The doctors could not test whether buckwheat actually causes physical symptoms in this patient because she declined further food challenges.
- A single case cannot show whether ground poppy seeds always cause worse reactions than whole ones in every allergic person.
Who paid
- Authors work at
- Ludwig Maximilian University, Germany
The paper
- Title
- Cross-sensitization between poppy seed and buckwheat in a food-allergic patient with poppy seed anaphylaxis
- Type
- Case report
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Oppel T, Thomas P, Wollenberg A (2006). Cross-sensitization between poppy seed and buckwheat in a food-allergic patient with poppy seed anaphylaxis. International archives of allergy and immunology. doi:10.1159/000092557Free full textPubMed 16601355DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error