Anaphylactic reactions to a psyllium-containing cereal

The riddle of response to cutaneous allergen exposure in patients with atopic dermatitis

The skin is the largest immunologic organ in the body and contains immune cells that play a role in both food allergen sensitization and desensitization. The dual allergen exposure hypothesis posits that sensitization to food allergens may occur with cutaneous exposure on inflamed skin, eg, atopic dermatitis, but early oral consumption generally leads to tolerance. However, only one-third of children with atopic dermatitis develop a food allergy, suggesting that there is a more complex mechanism for allergen sensitization. Emerging evidence suggests that the outcome of cutaneous allergen exposure is context-dependent and largely influenced by the state of the skin barrier with healthy skin promoting natural tolerance. Current research supports the ability to induce desensitization through repeated application of allergens to the skin, known as epicutaneous immunotherapy. Preclinical research with an occlusive patch has demonstrated a significantly reduced T-helper cell type 2-driven immunologic response when applied to intact, uninflamed skin and induction of a unique population of regulatory T cells that express a broader range of homing receptors, which may be able to maintain sustained protection. In clinical studies of children aged 1 through 11 years with a peanut allergy, epicutaneous immunotherapy with an occlusive patch led to significant desensitization with no major differences in efficacy or safety between children with and without atopic dermatitis. These data begin to answer the conundrum of how allergens that are applied to the skin can lead to both sensitization and desensitization, and future studies should enable us to optimize the power of the skin as a complex immunologic organ to treat allergic, autoimmune, and autoinflammatory disorders.

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.

Psyllium husk intake and risk of type 2 diabetes: an evidence-based scientific and regulatory review of a qualified health claim conducted by the US Food and Drug Administration

The US Food and Drug Administration (FDA) received a petition from a company requesting that FDA issue an authorized health claim for the relationship between psyllium husk and a reduced risk of type 2 diabetes. After an initial assessment of the available scientific evidence, FDA determined that significant scientific agreement was lacking for this substance-disease relationship, whereupon the company agreed to have its petition reviewed as a qualified health claim. This article describes the process FDA used in conducting an evidence-based review of the science underpinning the proposed claim and addresses certain safety issues associated with psyllium husk that FDA considered in its review of the petition. Of the 6 studies from which scientific conclusions could be drawn, as identified through FDA's review, psyllium husk significantly improved plasma glucose levels and insulin sensitivity in only 1 study. Therefore, FDA's enforcement discretion letter for this qualified health claim stated: "Psyllium husk may reduce the risk of type 2 diabetes, although the FDA has concluded that there is very little scientific evidence for this claim."

Food allergy: a practice parameter update-2014

This parameter was developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology (JCAAI). The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Food Allergy: A practice parameter update-2014." This is a complete and comprehensive document at the current time. The medical environment is a changing one, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, ACAAI, and JCAAI. These parameters are not designed for use by pharmaceutical companies in drug promotion.

[Plantago ovata]

Plantago ovata is a high fibre bulk forming laxative. It absorbs water and expands to provide increased bulk and moisture content to the stool. The increased bulk encourages normal peristalsis and bowel motility. Clinical Indications: Constipation, Fecal Incontinence, Hemorrhoids, Ulcerative Colitis, Appetite, Hyperlipidemia, Diabetes mellitus.

Psyllium-associated anaphylaxis and death: a case report and review of the literature

BACKGROUND

Psyllium use has increased significantly in the United States in part due to its lipid-lowering property. The increased prevalence of consumption has led to its recognition as an emerging food allergen.

OBJECTIVES

To report the case of a 42-year-old woman who experienced fatal anaphylaxis after ingesting a psyllium-based product and to review the literature.

METHODS

The MEDLINE database was searched for articles from 1966 to 2002 using the keywords psyllium or ispaghula and each of the following: allergy, hypersensitivity, anaphylaxis, and asthma. Both English and non-English articles were included.

RESULTS

Psyllium hypersensitivity has been well described in health care workers and pharmaceutical plant employees. Clinical manifestations of allergy range from upper respiratory tract symptoms on inhalation to anaphylaxis on ingestion. The prevalence of sensitization varies between these 2 groups. The allergenic epitope is not known.

CONCLUSIONS

We present a case of psyllium hypersensitivity that resulted in death. There is a clear association between atopy and psyllium allergy. The case underscores the fact that even nonprescription "natural" products can be harmful to people with allergies.

Unusual presentations of food allergy

OBJECTIVE

This presentation is designed to critically review information on presentations of food hypersensitivity reactions that may be considered unusual regarding the source or nature of allergen, route of exposure, or clinical manifestation.

DATA SOURCES

Information has been gathered primarily through a thorough search of the English literature relevant to human subjects. Some clinical cases were also included from the author's own clinical experience.

STUDY SELECTION

Information summarized here was critically selected on the basis of proven or acceptable scientific validity.

RESULTS

The findings indicate that food allergy presentation can be unusual in three main aspects. First, the offending allergen may not be the obvious food that was ingested or be a food protein incorporated in a nonfood product. Second, systemic reactions can be provoked by very minute quantities of food allergens that may even get access through noningestant routes, eg, inhalation, odor, skin contact, or mucous membrane contact. Third, the clinical manifestations are not limited to the few gastrointestinal, cutaneous, and respiratory symptoms with which we are generally familiar.

CONCLUSIONS

The extent of food allergy presentation is more than has been generally realized. Our awareness of such unusual presentations adds new knowledge and should prompt our interest in carefully evaluating patients with obscure allergic reactions for possible food allergy.

Chemicals in food and allergy: fact and fiction

The prevalence of the atopic diseases asthma, rhinitis and atopic eczema has increased in the past two to three decades. It is not unusual to read the statement that food additives and other chemicals in food increase the risk of allergy. From a theoretical standpoint chemicals in the diet may influence allergic sensitization and elicitation in different ways: (i) they may directly cause allergy because they are allergens or haptens; (ii) they may act as adjuvants facilitating allergy to other (dietary) components; (iii) they may modulate the immune system by direct immunotoxicity and in theory be able to change the balance from tolerance to IgE production; and (iv) they may trigger non-allergic intolerance reactions. With the present knowledge of chemicals in foods, the human exposure to these chemicals, and the described trends in this exposure, there is no supportive evidence confirming that chemicals in foods are contributing to the reported increase in the prevalence of atopic diseases.

Psyllium laxative-induced anaphylaxis, asthma, and rhinitis

A 69-year-old nurse was evaluated for a recent episode of anaphylaxis that had occurred after psyllium ingestion. She had experienced recurrent rhinitis and asthma related to psyllium exposure for the past 15 years. The diagnosis of psyllium hypersensitivity was established by a positive psyllium puncture skin test, an elevated psyllium-specific IgE level in serum, and a confirmatory soluble-antigen competitive inhibition test. The patient was symptomatic for several years, and this diagnosis was not considered until she suffered potentially life-threatening anaphylaxis. Psyllium hypersensitivity may be a more common phenomenon than is currently appreciated by physicians and other health-care providers.

Role of clinical laboratory in allergy testing

The clinical laboratory has a well defined role to play in the diagnosis and management of patients with allergy. Elevated serum levels of total IgE and/or allergen-specific IgE indicate that an IgE mediated event has occurred. Methods such as basophil degranulation and basophil or leukocyte histamine release can provide similar information. Sensitive and precise methods suitable for automation are available for quantitation of histamine in whole blood or plasma. Methyl histamine can be assayed in urine. Eosinophil cationic protein levels in serum can be used as an indicator of eosinophil activation in disorders such as asthma and atopic dermatitis. Similarly, serum mast cell tryptase levels can confirm or exclude an anaphylactic reaction both in life and as a cause of death. This review documents and compares commercially available methods for these assays and discusses their application to screening, diagnosis, and management of patients with allergy.