Occupational IgE-mediated psyllium allergy in contemporary gluten-free and vegan baking: A case of allergic rhinitis.

Psyllium (from Plantago ovata; ispaghula) is used as a dietary supplement and is supplied in the form of husk, granules, capsules, or powder. Consumers using psyllium-containing laxatives, healthcare workers handling these, and pharmaceutical workers in laxative-manufacturing plants are known to be at risk of sensitization and subsequent rhinitis, asthma, contact urticaria, and even anaphylaxis. To our knowledge, the case we present here is the first of baker's immunoglobulin E (IgE)-mediated occupational allergy due to psyllium exposure. Our patient, a 24-year-old female baker with no previous allergies, was referred to our clinic with suspected occupational rhinitis. After 1 year of baking with cereal flour or gluten-free flour-mix, she began to suffer from rhino-conjunctival symptoms during workdays. Skin prick tests with agents from the patient's workplace revealed allergies not only to wheat and rye flours but also to psyllium, with a remarkable 10 mm wheal. Subsequently, nasal provocation tests confirmed occupational allergic rhinitis to psyllium. We also found work-related sensitization to buckwheat, which she used in gluten-free baking. Due to the increased prevalence of celiac disease and the popularity of gluten-free and vegan food, psyllium has recently become a common ingredient in baking, used as a substitute for gluten or eggs. Bakers handle allergens such as these in high concentrations and this may lie behind the emergence of respiratory and dermal symptoms. It is essential to consider new or recenlty introduced materials as possible allergens if it is suspected that a baker has work-related respiratory or allergic symptoms.

Allergy to laxative compound (Plantago ovata seed) among health care professionals.

BACKGROUND: The seeds of Plantago ovata (psyllium, ispaghula) used in the manufacture of bulk laxatives are known to be the cause of occupational allergy (rhinitis, asthma) in health care and pharmaceutical workers. OBJECTIVE: We studied the prevalence of P ovata seed allergy among health care workers in geriatric care homes and compared it with a group of health care professionals not exposed to P ovata seed. Cross reactivity with Plantago lanceolata pollen was also studied. METHODS: Two groups of health professionals were recruited: 58 health care workers from geriatric care homes who were exposed daily to laxatives containing P ovata and 63 nonexposed health care professionals. The prevalence of allergy and sensitization to P ovata seed was determined based on clinical history, skin prick test, and analysis of specific immunoglobulin (Ig) E. IgE immunoblotting was performed to calculate the molecular weights of the P ovata seed allergens. Cross reactivity to P lanceolata pollen was studied by enzyme allergosorbent test (EAST) and immunoblot inhibition techniques. RESULTS: The prevalence of sensitization and clinical allergy to P ovata seed in the exposed group was 13.8% and 8.6%, respectively. No sensitization was observed in the nonexposed group. IgE-binding proteins of 17, 20, 25, 32-34, 54, 73-77, and > 97 kDa were identified. EAST inhibition and immunoblot inhibition demonstrated the existence of cross reactivity between P ovata seed and P lanceolata pollen extracts. CONCLUSIONS: The rate of sensitization to P ovata seed is high among health care workers in geriatric care homes (13.8%). A mild cross reactivity between P ovata seed and P lanceolata pollen was observed.

English plantain and psyllium: lack of cross-allergenicity by crossed immunoelectrophoresis.

BACKGROUND: English plantain (Plantago lanceolata) weed pollen and psyllium (Plantago ovata) husk dust are inhalant allergens. Because of the phylogenetic relationship between these plant species, cross-allergenicity has been a concern. OBJECTIVE: The purpose of this study was to investigate the possible cross-allergenicity of plantain and psyllium. METHODS: Homologous and heterologous crossed immunoelectrophoresis (CIE) were performed using a commercial English plantain pollen extract and an extract of psyllium seed embryo. Crossed radioimmunoelectrophoresis (CRIE) was performed using sera from subjects who were RAST positive only to plantain (group A), RAST positive only to psyllium (group B), RAST positive to both plantain and psyllium (group C), or RAST negative to both (group D). RESULTS: All of the group A plantain subjects showed IgE binding to at least one of the six plantain allergens in homologous plantain CRIEs while only one of the sera from the group B subjects reacted very weakly to these plantain allergens. In homologous psyllium CRIE, all group B subjects showed pronounced IgE binding to 2 to 7 of the seven psyllium allergens. Several of the plantain subjects demonstrated only very weak binding to psyllium allergens. Heterologous CRIEs demonstrated little relevant IgE binding. CONCLUSIONS: These results indicate that there is little cross-allergenicity between psyllium husk and English plantain pollen.

Antigenic and allergenic analysis of psyllium seed components.

The outer portions (husk) of psyllium seeds are a concentrated source of natural fiber used in some bulk-fiber laxatives and cereals. They are known to elicit respiratory allergic reactions after inhalation or ingestion among sensitized individuals. Antigenic and allergenic characterization of three psyllium-seed fractions (husk, endosperm, and embryo) was conducted with crossed immunoelectrophoresis (CIE), crossed radioimmunoelectrophoresis, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis to determine the source of psyllium allergenicity. Homologous CIE demonstrated psyllium endosperm and embryo extracts contained seven and four antigens, respectively. Husk extracts were too gelatinous to react by CIE. However, heterologous CIE profiles of endosperm or embryo extracts, reacted with antihusk antibodies, resulted in antigen-antibody precipitin peaks that matched the heavy staining precipitin lines of homologous reactions for endosperm and embryo, respectively. These results indicated that commercial-grade husk, endosperm, and embryo contained similar antigens. Extracts of all three seed components contained antigens that bound IgE antibodies in the sera of 11 psyllium RAST-positive individuals, as determined by crossed radioimmunoelectrophoresis. The few prominent husk protein/peptide bands resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were common in either embryo or endosperm. Immunoblots revealed common IgE reactive bands in all three seed fractions. Microscopic examination of the powdered commercial-grade psyllium (95% pure) revealed it contained endosperm and embryo particles. These immunologic, biochemical, and microscopic findings suggest that other contaminating seed components are primarily responsible for the allergenicity of commercial-grade psyllium-husk powder rather than the husk itself.

Anaphylactic reactions to a psyllium-containing cereal.

Historical data were obtained by questionnaire and telephone survey on 20 of 24 women with reported allergic reactions to a psyllium-containing cereal, Heartwise. Protein fractions from this new cereal, as well as from psyllium mucilloid and a psyllium-containing laxative, Metamucil, were extracted, quantitated, and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Patients' sera were collected, and specific IgE and IgG antibodies to these psyllium antigens were detected by immunoblotting techniques. Of the 20 women evaluated, all but six were nurses. Eighteen (90%) of the women had historical and/or laboratory evidence of atopy. Exposures included ingestion or dispensing of psyllium-containing products. Only three women denied prior exposure to psyllium. Symptoms developed shortly after small amounts of the cereal were ingested and most commonly included moderate to severe wheezing, throat and chest tightness, and urticaria. All the women required medical therapy, 11 (55%) in an emergency room. Specific IgE and IgG antibodies to various psyllium protein fractions were documented in all the subjects. It was concluded that individuals sensitized by occupational exposure to psyllium dust are at high risk for allergic reactions to ingested psyllium-containing products.

Prevalence of occupational asthma and immunologic sensitization to psyllium among health personnel in chronic care hospitals.

Psyllium is a high molecular weight laxative that can cause occupational asthma among health care workers who prepare this product for chronically ill patients. The prevalence of immunologic sensitization and occupational asthma to psyllium is unknown. We investigated the personnel of four chronic care hospitals, including two where four cases of occupational asthma had been confirmed the year preceding the trial. A questionnaire and skin prick tests with psyllium and various inhalants were administered to 193 of 248 (78%) of the workers who agreed to participate. Seventy-five subjects (39%) had a history of respiratory symptoms in normal life and/or respiratory symptoms and/or rhinoconjunctivitis after handling psyllium. Six (3%) showed skin reactivity to psyllium. Increased specific IgE antibodies were found in 20 of 162 of the sera that were tested (12%). In the second part of the study, a histamine inhalation challenge was performed on 70 of 75 (93%) of the subjects with a history suggestive of asthma and/or occupational asthma and/or skin reactivity to psyllium. Twenty (29%) had significant bronchial hyperresponsiveness. The six subjects with a history suggestive of occupational asthma (n = 3) and/or asthma (n = 6) and/or positive skin test results to psyllium (n = 6) had significant bronchial hyperresponsiveness and increased specific IgE levels. They all underwent specific inhalation challenges with psyllium in the laboratory. Four developed bronchospastic reactions (two immediate and two dual reactions). We conclude that by including the initial four cases reported in the year preceding the initiation of this trial, the prevalence of IgE sensitization to psyllium was between 5 (skin testing) and 12% (increased specific IgE levels).(ABSTRACT TRUNCATED AT 250 WORDS)

Anaphylaxis following ingestion of a psyllium-containing cereal.

Recently, psyllium hydrophilic mucilloid, a bulk-forming laxative, has been added to breakfast cereals for cholesterol-lowering effects. We report a case of a 60-year-old woman with no prior history of psyllium ingestion who developed anaphylactic symptoms after eating a psyllium-containing cereal. Her only previous exposure was dispensing a psyllium-containing laxative as a nurse. Immunoglobulin E-mediated sensitization was documented by skin testing and basophil histamine release. The literature is reviewed regarding allergic reactions to psyllium. Health care workers and pharmaceutical workers handling psyllium may be at increased risk due to sensitization from inhalation. Physicians and consumers should be aware of potential serious reactions from eating psyllium-containing cereals even without prior history of ingestion of psyllium.

Occupational asthma and IgE sensitization in a pharmaceutical company processing psyllium.

We assessed the prevalence of occupational asthma and IgE sensitization to psyllium in a pharmaceutical company producing psyllium hydrophilic mucilloid, which is used as a laxative. Workers were intermittently exposed, approximately 5 times/yr, for periods of less than 10 days. Of the 140 employees, 130 (93%) were studied before a processing period via a questionnaire spirometry (n = 125), blood sampling (n = 118), and skin prick tests (n = 120) with 7 common inhaled allergens as well as plantain and psyllium. Thirty-nine workers had a history suggestive of occupational asthma. Twenty-three of 120 (19%) showed a skin wheal diameter greater than or equal to 3 mm to psyllium and 31 of 118 (26%) had increased specific IgE antibodies; 39 (32%) workers had at least 1 of these 2 features. Subjects with a questionnaire suggestive of asthma or occupational asthma were further investigated by serial monitoring of peak expiratory flow rates and PC20 methacholine before and during the psyllium processing period. All workers had spirometry repeated during the processing period. Twenty-one subjects who had a PC20 less than or equal to 16 mg/ml (n = 10) and/or decreased their PC20 by a greater than or equal to 3.2-fold difference (n = 4) and/or changed their FEV1 by greater than or equal to 10% (n = 13) during the processing period were referred for inhalation challenges to psyllium in the laboratory. Five of the 18 workers for whom these tests were feasible gave an immediate bronchoconstrictive reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Occupational asthma in nurses handling psyllium.

Five nurses aged 31-55 years old had a history of asthmatic symptoms after being exposed to psyllium that they prepared and distributed to patients. They had been nurses for 9-20 years and had reported asthmatic symptoms related to work in the past 3-12 months. They reported symptoms of rhinoconjunctivitis and all were atopic but only one had a previous history of asthma. Four of the five tested subjects had an immediate skin reaction to a commercial psyllium extract. All had IgE antibodies to psyllium. At the time that they were investigated, four out of the five had a significant increase in bronchial responsiveness to methacholine (PC 20 less than 8 mg/ml). Inhalation challenges with psyllium caused isolated immediate (one subject) and dual reactions (three subjects). One subject exposed for only 1 min to the psyllium powder experienced a severe immediate bronchospastic reaction, which required intubation for 3 h with complete functional recovery thereafter. This experience illustrates the precautions necessary, with the inclusion of a cautious dose-response approach, even with an 'occupation-type' challenge in the laboratory.

Experimental assessment of the allergenicity of a psyllium-containing laxative.

The allergenicity of psyllium was investigated using the Guinea Pig Maximation Test. Four of 12 animals gave positive skin reactions. Subsequent inhalation challenge of the same animals yielded respiratory hypersensitivity reactions in four of the animals. Two animals gave both skin and respiratory responses. The mosaic of respiratory and dermatologic symptoms demonstrated by animals resembled the pattern of findings reported in clinical studies. Results of SDS-acrylamide gel electrophoresis, immunoblot and protein determinations of aqueous psyllium extracts failed to indicate the presence of protein. Spectrophotometric studies suggested that the extract was a gum with a molecular weight greater than 14,000 daltons.

Workplace allergenicity of a psyllium-containing bulk laxative.

IgE antibodies specific to psyllium were demonstrated by RAST in a patient with work-place-related asthmatic and dermatological reactions. Antibodies were not cross-reactive with the related plant, English plantain.

Anaphylaxis following psyllium ingestion.

Psyllium is a hydrophilic agent found in many bulk laxative preparations. We report the occurrence of an anaphylactic reaction in a patient after ingestion of a psyllium-containing laxative. IgE mediation of the reaction was suggested by a positive immediate skin test to psyllium, positive passive transfer skin test, lack of skin response during passive transfer with heat treated serum, and an elevated IgE (RAST) to psyllium seed.

Dust exposure challenge test as a measure of potential allergenicity and occupational disease risk in handling of Ispaghula products.

It is known that workers in the pharmaceutical industry, and nurses, can become sensitized and develop allergic respiratory symptoms by handling bulk laxatives containing Ispaghula powder. Fifteen individuals allergic to Ispaghula were challenged with a commercially available Ispaghula product and three other products manufactured in a way to make them less dusty. The results show that the use of products with smaller amounts of airborne particles results in a lower incidence of symptoms and thus probably reduces the potential occupational risk of sensitization to the Ispaghula allergen.

Serum IgE antibodies to psyllium in individuals allergic to psyllium and English plantain.

Psyllium is used in the production of bulk laxatives. By means of the RAST assay the authors demonstrated that psyllium can induce the formation of IgE antibodies. They also demonstrated that IgE antibodies in individuals allergic to English plantain may cross react to psyllium.

Ispagula powder: an allergen in the work environment.

Bulk laxatives based on ispagula powder have given no known allergic side effects when administered perorally. Twenty-seven out of 64 workers in a pharmaceutical factory developed rhinitis, conjunctivitis or asthma when engaged in the packing of ispagula husks, an operation which gives rise to dust. The symptoms are accounted for by a type 1 allergy acquired from ispagula husks. This allergy can be demonstrated by intracutaneous and provocation tests. Occupational health measures were taken which reduced the dust content to a minimum; thereafter only one new case of sensitization was recorded during the next 24 months of observation. Five similar cases were reported among nursing staff exposed to the dust of ispagula while administering doses of bulk laxative.