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Keywords:

  • anaphylaxis;
  • celiac disease;
  • gluten-free diet;
  • sesame

T he generally increasing consumption of sesame might explain the growing frequency of reported cases of immediate-type systemic reactions after ingestion of sesame seeds in recent years ( 1–4). Sesame seeds are often present in gluten-free foods (e.g., bread, cakes, pastries, and biscuits) used to treat celiac patients.

We report herein the case of a celiac patient with systemic reactions due to sesame ingestion. D.F., an 18-year-old woman, was diagnosed as having celiac disease at the age of 4 years. The diagnosis was based on clinical symptoms (chronic diarrhea, vomiting, and malnutrition) and jejunal biopsy. After the diagnosis, the patient was put on a gluten-free diet, which led to clinical recovery and symptom disappearance. One year ago, the patient presented two severe systemic reactions after eating food containing sesame. The first episode involved facial erythema, pruritus, and conjunctivitis a few minutes after she ate biscuits. The second episode, 1 week later, occurred after she ate sesame-containing bread and consisted of vomiting, cough, generalized itching, and laryngeal edema. The latter episode required emergency treatment including the administration of subcutaneous epinephrine and intravenous corticosteroids.

She had no personal or familial history of allergic disorders; routine skin prick tests were all negative for a standard series of common inhalant allergens and for an extensive panel of food allergens. Prick by prick tests with poppy seeds, flaxseed, pine nuts, hazelnut, and sunflower seeds were negative. Prick by prick tests performed with sesame seeds and sesame oil did not show any skin reaction. No specific IgE (Pharmacia CAP System) antibodies against sesame seeds and common inhalant allergens were found. The total serum IgE was 22.3 kU/l.

A double-blind, placebo-controlled food challenge (DBPCFC) was carried out in the outpatient clinic with full facilities for resuscitation. The challenge was performed with sesame seeds (5 g) masked in bread. The placebo bread was baked with hazelnut (5 g).

No adverse reaction was observed to the oral intake of hazelnut-containing bread.

About 15 min after the patient ate a small amount of sesame bread, generalized flushing and hives, abdominal pain, cough, and dyspnea appeared. She was promptly treated with subcutaneous epinephrine, intravenous corticosteroids, and intramuscular antihistamine, and the symptoms disappeared within 1 h. At the onset of symptoms, the FEV1 fell to 61% of the predicted value and returned to normal values after inhaled salbutamol and the above-mentioned therapy ( Fig. 1). No increase in serum tryptase was observed (12.4 μg/ml, normal range 4.8–13.5 μg/ml). Non-sesame-specific IgE could be detected 12 weeks after the DBPCFC.

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Figure 1. FEV1 before and after food challenge with sesame.

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In the present case of systemic reaction to sesame, no skin positivity was present and no specific IgE could be found; moreover, in a recent paper, the poor sensitivity of specific antibodies against sesame has been reported ( 4). On the other hand, the negative result obtained with prick by prick tests allows us reasonably to exclude an IgE-mediated reaction.

This result agrees with other studies showing that sesame can induce non-IgE-mediated anaphylaxis ( 2–4). In our patient, no increase in serum tryptase was found. Serum tryptase usually rises in 1 h and remains high for several hours after anaphylaxis induced by Hymenoptera venom or drugs ( 5), whereas it is well known that tryptase rarely increases after anaphylaxis due to food ( 6).

The reason for this is not clear, but this fact suggests that cells other than mast cells, such as basophils, monocytes, or macrophages, may be more important in food-induced allergic reaction. Our DBPCFC was performed with sesame seeds hidden in baked bread; therefore, there are relevant allergens in sesame which are heat resistant.

The potency of particular foods to induce an anaphylactic reaction appears to vary and is also dependent upon the sensitivity of the individual. Because the gluten-free diet for celiac patients often contains sesame seeds, we underline the potential seriousness of a missed diagnosis of sesame allergy. The life-threatening nature of anaphylaxis makes prevention the cornerstone of therapy. If the causative food allergen is not clearly delineated, an investigation to determine the cause should be promptly initiated. An early diagnosis based on a detailed allergologic history and a cautious DBPCFC may prevent further, possibly life-threatening exposure to sesame.

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Footnotes
  1. Nonallergic hypersensitivity in a patient with celiac disease.