Clinical Experience
IgE-mediated reactions
Poppy seed commonly induces symptoms of food allergy in sensitised individuals, which may be confirmed by SPT and IgE antibody determination. It has been suggested that the prevalence of Poppy seed allergy is increasing as a result of the increased number of vegetarian and ethnic dishes.
Immediate-type allergic reactions range from mild local symptoms to severe anaphylactic reactions, and may involve the gastrointestinal, respiratory or skin systems (1,7-10). A patient who experienced an immediate-type hypersensitivity reaction against Poppy seed described symptoms of swelling of the oral mucosa, vomiting, respiratory distress, and urticaria. Poppy seed-specific IgE was demonstrated (5).
Other studies have described similar severe immediate-type reactions to Poppy seed; these studies include a report of 3 patients in whom SPT and IgE antibody test were positive (5). Immediate-type allergy caused by Poppy seed in a 52-year-old man was described. Symptoms included epigastric pain, angioedoema, and respiratory distress a few minutes after eating Poppy seed cake. SPT and IgE antibody test were positive (7). A 17-year-old female had an apparent food-allergic reaction after ingestion of a Poppy seed cake. Laboratory investigation led to the identification of a novel cross-sensitisation with Buckwheat (6).
Anaphylaxis and food-dependant exercise-induced anaphylaxis have been reported (11-12). Food-dependant exercise-induced anaphylaxis was described in a 46-year-old man who had experienced 4 episodes of generalised urticaria, all occurring within 1 hour after ingestion of a Poppy seed cake. These episodes occurred only in combination with exercise, although he had been eating this cake every Friday for about a year. SPT for Poppy seed was positive and allergen-specific IgE was 13.4 kUA/l. Oral challenges without exercise were negative. On follow up, the patient reported that he had continued to eat Poppy seed cake every Friday, but that only in combination with gardening had generalised urticaria occurred (13).
A study described immune and non-immune hypersensitivity reactions to Poppy seed in a 21-year-old woman and a 32-year-old man, in both of whom life-threatening symptoms and signs of anaphylaxis developed after consumption of Poppy seeds in various situations, e.g., after consumption of a roll with Poppy seeds on it, and of a cake prepared on a moulding board on which Poppy seed paste had previously been squeezed. The female patient was reported to have a history of atopy, and in her case skin reactivity was detected to a range of pollen allergens and to Hazel nuts, whereas SPT for various allergens was negative for the male. In the female, the IgE antibody levels were raised for Celery and nut mixture but negative for Poppy seed, whereas in the male the IgE antibody levels for Poppy and nut mixture were both raised (Class 2). In the male patient, among SPT with topical anesthetics and narcotic analgesics derived from Poppy, tests were positive for xylocaine and codeine. The authors concluded that hypersensitivity to Poppy seed may occur through IgE-dependent or non-immune mechanisms, and that a history of atopy is not completely determinant (13).
Inhalation of Poppy seed resulting in erythema, angioedema, conjunctivitis, and dyspnoea in a 16-year-old boy was described. Skin reactivity was present for Poppy seed, Hazel nut, and Chickpea. IgE levels for Poppy seed, Hazel nut, and Peanut were 3.36 kUA/l, 1.5 kUA/l, and 6.17 kUA/l, respectively. This is the first report on inhalant allergy to Poppy seed (14).
Allergic contact dermatitis and contact urticaria have been reported to closely related family members, Papaver rhoeas and Papaver nudicaule (Icelandic poppy) (15-16).
Other reactions
IgE reactions have also been reported to Poppy shells, which contain the seeds. Six of 28 workers in a pharmaceutical factory producing morphine and extracting other alkaloids from shells of Papaver somniferum were found to have clinical symptoms of sensitisation to Poppy. Skin reactivity was demonstrated. A bronchial provocation test was found to be positive for 4 workers, and in all of these cases IgE antibodies were demonstrated to an aqueous extract of P. somniferum. Histamine release tests using the same antigen were also positive in the 4 samples from sensitised patients. A major protein of around 52 kDa was isolated. These findings suggest that P. somniferum allergy is mediated by an IgE mechanism and not by a pharmacological or toxic effect of the alkaloids or polyphenols (2).
This plant contains a number of very toxic compounds, many of which are extracted and used as pain killers, etc. They are also used to make various narcotic drugs, which do not all fit the stereotypes of highly refined “street drugs”. Danish Poppy capsules contain 3-5 mg morphine per capsule, and the content of morphine in opium exuded from the capsules may amount to 24%. This has resulted in misuse, as both fresh and dried Poppy capsules can yield “opium tea”. During the period 1982-1985, 7 casualties occurred among drug addicts in Denmark that were solely or partly caused by these Opium capsules (17). A patient presenting with dependence on Opium poppy tea has also been reported. But Poppy tea drinking, although previously described in certain parts of the UK, rarely presents as a dependence syndrome (18).
Because Poppy seed may be an ingredient in ordinary confections, caution is warranted in environments with drug testing. In a study in which 9 volunteers ingested cake containing Poppy seed, several urine specimens contained morphine with concentrations higher than 1 microg/ml, and the peak values were approximately 10.0 µg/ml. Because the International Olympic Committee has set a cut-off for morphine at 1 µg/ml, athletes could fall foul of testing after consumption of products containing Poppy seeds (19).
