D2.272 - Anaphylaxis caused by Psyllium

Psyllium, derived from the seeds and husks of Plantago ovata, is commonly used as a laxative due to its hydrocolloid properties. It is also utilized in gluten-free bread production. Few cases have been published reporting psyllium as a cause of anaphylaxis, and most of them involve its use as a laxative rather than a food additive. 

A 59-year-old man patient presented with nausea, dyspnea, pruritus, and a generalized rash after 30 minutes of the ingestion of mayonnaise, Falafel meatballs (containing chickpeas, pre-fried fava beans with onion and vegetable oils, wheat flour, cilantro, garlic powder, mint, cumin, pepper, corn starch, and psyllium fiber) and beer. Upon admission to the hospital emergency department, oxygen saturation levels ranged from 87-90%, with a pO₂ of 59.4 mmHg. Generalized rash was observed in the trunk and extremities, though there was no uvular edema, angioedema, or wheezing. Treatment included intravenous fluids, oxygen therapy, salbutamol, and intravenous pantoprazole, dexchlorpheniramine, hydrocortisone and methylprednisolone, resulting in symptom improvement within 5 hours.

The patient subsequently tolerated all implicated foods except for fava beans and psyllium fiber. As far as the patient is aware, mustard neither sesame were not included between the ingredients of the meatballs, and sesame was also tolerated after the reaction. 

Four months later, the patient underwent further evaluation in our clinic, including a comprehensive blood analysis, specific IgE testing, basal tryptase determination, prick test with a battery of different foods, and prick-by-prick test with the non-tolerated foods or foods with a positive prick result. 

Skin prick tests with food proved to be positive with mustard and sesame, and negative with the rest of food and LTP. Prick-by-prick test was positive with psyllium (7 mm of maximum diameter of the wheal), being negative with fava beans, mustard, and sesame. Blood analysis showed normal hematology and biochemistry results. Basal tryptase level was 5.93 μg/L (not measured during the acute episode). Total IgE was normal (48.9 IU/mL), and specific IgE testing revealed positivity for sesame (0.84 kU/L) but negativity for fava beans, mustard, alpha-gal, Anisakis, Ascaris, and omega-5 gliadin. 

We present a rare case of IgE food anaphylaxis causes by psyllium diagnosed by a suggestive clinical history, and a positive prick-by-prick test with psyllium.