This article was posted on Medscape today.

http://www.medscape.com/viewarticle/527696

I have heard a few stories on news regarding this report with all of them making the point that doctors needs to consider history of the patient's exposure and reaction to suspected allergen. Making the point that trial and error - by eliminating foods or adding them to the diet - is the best way to detect for food allergies.

I can't open the link. Need a username and password.

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I have an account. :wink:


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New Guidelines Issued for Food Allergies CME/CE
News Author: Laurie Barclay, MD
CME Author: Désirée Lie, MD, MSEd

Disclosures (http://www.medscape.com/viewarticle/527696_author)
To earn CME credit, read the news brief along with the CME information that follows and answer the test questions.

Release Date: March 16, 2006</B>; Valid for credit through March 16, 2007



Credits Available
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Family Physicians - up to 0.5 AAFP Prescribed continuing medical education credits for physicians ;
Nurses - 0.6 ANCC continuing education contact hours for nurses (0.0 credits are in the area of pharmacology)
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March 16, 2006 — Guidelines created by a joint task force help clarify the diagnosis and management of true food allergies. They are published in the March issue of the Annals of Allergy, Asthma and Immunology.
"Food allergy, as defined for the purposes of this document, is a condition caused by an IgE-mediated reaction to a food substance," write Jean A. Chapman, MD, and colleagues from the American Academy of Allergy, Asthma and Immunology. "Adverse reactions to foods may also occur due to non–IgE-mediated immunologic and nonimmunologic mechanisms.
The authors note that food allergy is an important subset of all adverse food reactions that is often misunderstood. Because of important new scientific findings, the evaluation and management of food allergy have changed significantly in recent years. Potentially fatal food allergy to peanuts and tree nuts is becoming more common or at least more widely recognized.
"This has resulted in an increased awareness among the general public, leading to policy changes in schools, eating establishments, and the airline industry," the authors write. "At the same time, diagnostic evaluation in patients suspected of having food allergy has become both more sophisticated and more challenging."
The objectives of this practice parameter on food allergy include improved understanding of food allergy by healthcare professionals, medical and nursing students, interns, residents, fellows, managed care executives, and administrators; establishing guidelines and support for the practicing clinician; and improving the quality of care for patients with food allergy. However, these guidelines are not intended to replace clinical judgment or to establish a protocol for all patients.
During their lifetime, about one quarter of the population will have some sort of adverse reaction to food, especially during infancy and early childhood. Based on the underlying pathophysiologic changes, these adverse reactions are classified as food allergy, food intolerance, pharmacologic reactions, food poisoning, and toxic reactions. True food allergy is relatively uncommon, but individuals with atopy are at greater risk, especially infants with moderate to severe atopic dermatitis. Children who develop an IgE-mediated allergy to one food are at increased risk of developing IgE-mediated reactions to other foods and/or inhalants. Because the true prevalence of food allergy is much lower than the number of adverse reactions to food, healthcare professionals should not perpetuate false assumptions about food allergy.
"If a patient is incorrectly diagnosed as having a reaction to a food, unnecessary dietary restrictions may adversely affect quality of life, nutritional status, and, in children, growth," the authors write. "Severely restricted diets may lead to the development of eating disorders, especially if they are used for prolonged periods, or may make the patient susceptible to false claims of scientifically unproven and often costly techniques that offer no actual benefit. In addition, unintentional exposure to foods falsely thought to cause adverse reactions can provoke unnecessary panic and use of medications that have potentially potent adverse effects."
IgE-mediated food allergies may occur by sensitization through the gastrointestinal tract, sensitization through the respiratory tract to airborne proteins identical or homologous to those in particular foods, or sensitization through epidermis with impaired barrier function. Thenature and dose of antigen, host immaturity, genetic susceptibility, rate of absorption of a dietary protein, and the conditions of antigen processing may all affect mucosal adaptive immunity in the gastrointestinal tract.
Molecular and immunologic techniques can help determine which allergens or epitopes of an allergen in a particular food may be responsible for specific clinical outcomes. Immune responses to a particular allergen may differ based on the method of exposure and the condition of the food.
Sensitivity to most food allergens, such as milk, wheat, and egg, tends to resolve in late childhood, but allergies to peanut, tree nuts, and seafood are likely to be lifelong. Peanut allergy, which affects approximately 0.6% of the general population, is the most common cause of fatalfood-induced anaphylaxis, especially in adolescents with asthma. Allergies to fruits and vegetables are the most common food allergies reported by adults, and these maydevelop later in life because of shared homologous proteins with airborne allergens such as pollens.
Risk factors for developing food allergy include a personal or family history of atopy or food allergy, maternal consumption of major food allergens during pregnancy or breast-feeding, atopic dermatitis, and transdermal food exposure. For infants at increased risk, breast-feeding and avoidance of highly sensitizing and/or solid foods at a young age may help reduce this risk.
Symptoms of food allergy may be mild, develop gradually, and be limited to the gastrointestinal tract, or they may be severe, rapidly progressing, life-threatening anaphylactic reactions triggered by even small amounts of food allergen. There is a strong temporal relationship between the onset of the reaction and exposure to a specific food or food additive, and symptoms may include skin manifestations, gastrointestinal symptoms, respiratory symptoms, hypotension, and laryngeal edema, occurring separately or together. Anaphylaxis may occur in highly sensitive patients or when triggering foods are ingested before or after exercise.
Evaluation of food allergy should begin with a detailed history featuring a list of suspect foods, the quantity of food triggering a reaction, the reproducibility of the reaction and its temporal relationship to food ingestion, time elapsed between exposure and reaction, clinical symptoms, resolution of symptoms when the suspect food is eliminated, and duration of symptoms overall and after each exposure. A written record of dietary intake may be helpful.
Physical examination should focus on suspected targeted organ systems including the skin, lungs, and gastrointestinal tract, and it should reveal or rule out alternative diagnoses to food allergy. Atopic disorders including asthma, atopic dermatitis, and allergic rhinitis increase the likelihood of food allergy.
Skin prick or puncture tests may be useful for screening. Commercial food extracts from foods with stable proteins, such as peanut, milk, egg, tree nuts, fish, and shellfish, reliably detect specific IgE antibodies in most patients, but extracts from fruits, vegetables, and other foods containing labile proteins are less reliable. In the latter case, pricking the food and then the patient may be helpful. However, skin or in vitro test results may remain positive even when the patient's skin is no longer clinically sensitive.
Intracutaneous or intradermal skin tests are not recommended because they are potentially dangerous, overly sensitive, and associated with an unacceptable rate of false-positive reactions. A positive skin test result has a positive predictive value of no greater than 50%, whereas a negative skin test has a negative predictive value of 95% or greater, virtually ruling out an IgE-mediated mechanism. Because allergy to multiple foods is uncommon, skin testing should be selective for suspected foods. Larger wheal-flare reactions on prick or puncture tests and higher concentrations of food-specific IgE measured by in vitro tests are correlated with a greater likelihood of reaction.
In vitro tests to evaluate possible IgE-mediated reactions may be especially valuable in patients with a history of a life-threatening reaction to the suspected food; in those with medical conditions, such as extensive atopic dermatitis or dermatographism that could hinder interpretation of skin test results; in those with a nonreactive histamine control; or in pregnant women. Patients with a history of anaphylactic reaction and positive test results for specific IgE antibodies usually require no further evaluation.
Other tests being investigated for their utility in diagnosing IgE-mediated reactions to foods include atopy patch tests, hair analysis, food specific IgG or immune complex assays, and newer versions of the previously disproved cytotoxic tests. However, provocation-neutralization is considered disproved as a diagnostic method in allergy.
Challenge with a suspected food may help to determine if test results were falsely negative or falsely positive, especially if done in a double-blind, placebo-controlled fashion. Consultation with an allergist-immunologist may benefit patients who have a history of reactions to foods that could be IgE-mediated.
Managing food allergy relies primarily on avoiding exposure to foods suspected or proven to be responsible for the patient's symptoms based on history and appropriate tests. If this is not possible, patients with chronic symptoms may benefit from an elimination diet. However, patients have an increased risk of unintentional food allergen exposure in special circumstances including schools and restaurants. The patient and/or the patient's advocate should be educated to read labels and to recognize that unfamiliar terms may indicate the presence of a food allergen.
Avoiding the identified food allergen may improve the likelihood that tolerance will develop with time, especially with cow's milk, egg, and soy. There are currently no known oral or parenteral agents consistently shown to prevent IgE-mediated reactions to food, and such measures should not be relied upon. Immunotherapy to food proteins is currently experimental. Injectable epinephrine is the treatment of choice for an anaphylactic reaction of any cause.
"For this reason, patients who have experienced IgE-mediated reactions to a food or their caregivers should be educated and provided with injectable epinephrine to carry with them," the authors write. "Because anaphylactic reactions may be prolonged or biphasic, it is reasonable to instruct the patient to carry more than one epinephrine injector, to seek immediate medical care after a reaction, and to be monitored for an appropriate period."
Ann Allergy Asthma Immunol. 2006;96:S1-S68
Learning Objectives for This Educational Activity

Upon completion of this activity, participants will be able to:

Describe the pattern, basis, and diagnosis of IgE-mediated and other food allergies.
List management guidelines for IgE-mediated food allergies.Clinical Context

According to the authors of the guidelines, the prevalence of potentially life-threatening food allergy to peanuts and tree nuts is increasing, leading to increased awareness and policy changes in schools, restaurants, and the airline industry in the United States. Adverse reactions to food affect some 25% of the population with the highest prevalence during childhood and infancy. Such reactions may be classified as food allergy, food intolerance, food poisoning, pharmacologic reactions, and toxic reactions.
Diagnostic evaluation of food allergies has become more challenging and sophisticated, according to the authors, and these guidelines provide practitioners with an evidence-based approach to the diagnosis and management of IgE-mediated allergic food reactions. Individuals with atopy, or with pollen or latex sensitivity are more likely to develop food allergies compared with the general population, with the highest incidence in infants with moderate to severe atopic dermatitis. IgE-mediated response to food represents only a small percentage of all adverse reactions to foods; its prevalence ranges from 2% to 5% and has definite ethnic variation.
These guidelines are based on a review of the medical literature and expert consensus of the Joint Task Force on Practice Parameters, with a goal toward improving understanding of food allergy, to guide clinicians, and to improve quality of patient care.
Study Highlights

In children of parents with asthma, the rate of observed food allergy may be 4 times higher than in the general population.
IgE-mediated food reactions may occur as a result of gastrointestinal sensitization, respiratory tract sensitization, or sensitization through the epidermis.
Immune responses include acute IgE-mediated, local inhalational, systemic, and cell-mediated reactions (eg, atopic dermatitis and celiac disease).
Sensitivity to most food allergens, such as milk, wheat, and egg, tend to remit in late childhood.
Sensitivity to peanut, tree nuts (walnuts, cashew, Brazil nut, pistachio), and seafood are likely to continue throughout life.
Allergies to fruits and vegetables tend to develop later in life as a consequence of shared homologous proteins with airborne allergens (eg, pollen).
Anaphylaxis after exposure to foods reflects reactions of respiratory, dermatologic, cardiovascular, and other organ systems.
In children, anaphylaxis occurs most commonly after ingestion of peanuts, other legumes, tree nuts, fish, shellfish, milk, and eggs.
Diagnosis requires a detailed history of exposures and targeted physical examination.
Initial evaluation may include skin prick or puncture tests.
Commercial food extracts with stable proteins (eg, peanut, milk, egg, tree nuts, fish, shellfish) are reliable to detect IgE antibodies in most patients.
Extracts from foods with more labile proteins (eg, many fruits and vegetables) are less reliable for diagnosis.
Intradermal skin tests are not recommended as they are dangerous.
A positive skin test has a positive predictive value (PPV) of less than 50% (ie, not specific) but a negative skin test has a negative predictive value (NPV) of more than 95% (ie, highly sensitive) and can reliably rule out IgE-mediated food allergy.
Double-blind, placebo-controlled food challenge is most likely to provide a high PPV in conjunction with a careful history.
In vitro serum tests are useful in patients with a history of life-threatening reaction, with medical conditions, a nonreactive histamine control, and in pregnant women.
If a patient has a history of anaphylactic reaction with a positive test for IgE specific antibodies, no further evaluation is usually required.
Provocation-neutralization is considered disproved as a diagnostic method.
Hair analysis, food-specific IgG, cytotoxic tests, and immune complex assays are considered experimental or unproven.
Adverse reactions to food additives (such as tartrazine) are rare.
Monosodium glutamate is a rare cause of angioedema, urticaria, or bronchospasm in patients with asthma. Sulfites produce bronchospasm in 5% of the population with asthma.
Food allergy prevention strategies include breast-feeding, maternal dietary restriction during breast-feeding, late introduction of solids and allergenic foods, and the use of hypoallergenic infant formulas although effectiveness of the strategies has not been established.
Avoidance of allergens is the key management strategy.
Because elimination diets may lead to malnutrition or other serious adverse effects (eg, personality change), every effort should be made to ensure that the dietary needs of the patient are met and that the patient and/or caregiver(s) are fully educated in dietary management measures to prevent inadvertent exposure to known or suspected allergens.
Injectable epinephrine should be given to patients or caregivers of patients with a history of IgE-mediated systemic reactions.
Delay in epinephrine administration is the most common cause of fatalities, with peanuts and tree nuts accounting for most fatal and near-fatal reactions.Pearls for Practice

IgE-mediated food allergies may be diagnosed by careful history, skin prick or puncture, and in vitro serum tests.
The main management strategies for IgE-mediated food allergy are avoidance and use of injectable epinephrine in those with a history of systemic reaction.http://images.medscape.com/pi/global/ornaments/spacer.gif
http://images.medscape.com/pi/global/ornaments/spacer.gif1. According to these guidelines, which of the following is recommended for diagnostic evaluation of IgE-mediated food allergy? (Required for credit) http://images.medscape.com/pi/global/ornaments/spacer.gifIntradermal skin testshttp://images.medscape.com/pi/global/ornaments/spacer.gifSkin prick testshttp://images.medscape.com/pi/global/ornaments/spacer.gifHair analysishttp://images.medscape.com/pi/global/ornaments/spacer.gifProvocation-neutralizationhttp://images.medscape.com/pi/global/ornaments/spacer.gif
http://images.medscape.com/pi/global/ornaments/spacer.gif2. A new mother with asthma would like to reduce the risk of IgE-mediated food allergy in her infant. According to this review, which of the following is not a potentially useful strategy? (Required for credit) http://images.medscape.com/pi/global/ornaments/spacer.gifBreast-feedinghttp://images.medscape.com/pi/global/ornaments/spacer.gifLate introduction of solidshttp://images.medscape.com/pi/global/ornaments/spacer.gifUse of hypoallergenic infant formulahttp://images.medscape.com/pi/global/ornaments/spacer.gifProgressive desensitization of motherhttp://images.medscape.com/pi/global/ornaments/spacer.gif




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News CME is designed to keep physicians and other healthcare professionals abreast of current research and related clinical developments that are likely to affect practice, as reported by the Medscape Medical News group. Send comments or questions about this program to cmenews@medscape.net (cmenews@medscape.net).

Medscape Medical News 2006. ©2006 Medscape
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The material presented here does not necessarily reflect the views of Medscape or companies that support educational programming on www.medscape.com (http://www.medscape.com). These materials may discuss therapeutic products that have not been approved by the US Food and Drug Administration and off-label uses of approved products. A qualified healthcare professional should be consulted before using any therapeutic product discussed. Readers should verify all information and data before treating patients or employing any therapies described in this educational activity

I glanced over it and it is the same old stuff we hear. This is a good site and very reliable for the most part so I check in from time to time to see what is new.

Will read this more thoroughly later. Thanks Pam!

I think you don't really have an account and you typed all that up by hand ... :rolling:

I think you don't really have an account and you typed all that up by hand ... :rolling:

Egad! Even I am not that FAST!:smt118 Thanks for the reminder on the marathon typing fest I had for sensory and speech postings. :smt108 I still have pain from that!:comp03:

:haha:

Thanks Leigh for copying and pasting. This updated report is significant as it is asking doctors to more closely consider the history over skin testing results which can be a good screening tool but are not as accurate as trial and error. This may be old news to some of us but parents not as familiar with allergy testing may find this interesting.

Good point Pam. :wink: Curran had absolutely NO skin reaction to milk, has a low RAST to it, and in reality reacts violently to it. His peanut wheal was massive and his RAST was not as bad as his cashew, which he has never ingested to my knowledge. It is confusing at times to make your way through the results.

Testing still is not perfect and I do very much agree with trial and error, even where IgE mediated responses are negative as it is clear these tests are a "point in time" indicator. We have been using the same methods of testing for so long now that we are bound to find a more efficient and accurate way at some point. Trial and error or blind studies leave little grey area for many. It sure has been illuminating for us.