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Crohn's Disease Forum » Diet, Fitness, and Supplements » Timing of food consumption and food allergy testing


10-01-2016, 08:58 PM   #1
7vNH
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Timing of food consumption and food allergy testing

After searching the internet a bit, I didn't find anything that talked about the timing of eating food in relation to getting the blood drawn for the food allergy test.

I know not everyone believes that testing for an immune response to delayed food reactions caused by antibodies IgG, IgA, IgM and IgD is scientifically sound, but I'd rather presume that _IF_ one were to perform this testing, then how long before the test would you want to consume all the various foods?

What I presume is that if a food has not been consumed "recently", then it would stand little chance of showing-up as positive for the antibodies. That would mean it would be wise to consume as many possible suspect foods as possible before the blood draw.

My question is how long would it take for the antibodies to become available, and how long would they linger after the last instance of a specific food. If you can find a reference on the topic, that would be fantastic. Thanks.
10-02-2016, 09:03 AM   #2
my little penguin
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Have you looked at egids ?
Since that disease is a mixed ige delayed reaction
Sometimes not often there is success with patch testing
Otherwise testing Igg igM etc is typically not particularly helpful
Have you kept a food diary ?
For ds he was placed on an elimination diet and only one food (single ingredient) was added every three days to determine if any thing was a trigger
We were able to isolate more than a few triggers that way

They also test for eoe ec etc by trailing one food at a time for a few months then scoping
To be able to see the reaction caused in the gut

There really isn't any papers or studies for timing like your asking since the process of testing igg igm etc would have to be a valid way to predict delayed reactions which so far I haven't seen anything

Only patch testing since it leaves the allergen on the skin for days

Patch test

Patch testing is generally done to see whether a particular substance is causing allergic skin irritation (contact dermatitis). Patch tests can detect delayed allergic reactions, which can take several days to develop.

Patch tests don't use needles. Instead, allergens are applied to patches, which are then placed on your skin. During a patch test, your skin may be exposed to 20 to 30 extracts of substances that can cause contact dermatitis. These can include latex, medications, fragrances, preservatives, hair dyes, metals and resins.

You wear the patches on your arm or back for 48 hours. During this time, you should avoid bathing and activities that cause heavy sweating. The patches are removed when you return to your doctor's office. Irritated skin at the patch site may indicate an allergy.
From
http://www.mayoclinic.org/tests-proc...t/prc-20014505
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10-02-2016, 09:05 AM   #3
my little penguin
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Abstract
Eosinophilic esophagitis (EoE) is a clinicopathologic disease of increasing prevalence in children and adults. The triggering antigen in EoE is often a food that initiates a cascade of Th2 associated interleukins such as IL-5, -13, and chemokines such as eotaxin-3 as well as esophageal eosinophilia and mastocytosis. Amino acid based formulas have high efficacy rates in EoE and constituted the first evidence for food triggered esophageal eosinophilia. Animal models have demonstrated the sufficiency of food antigens in triggering both the inflammatory and remodeling complications of EoE. Food elimination diets followed by single food introduction with repeat biopsy have proven the efficacy of empiric and allergy testing based elimination diets in children and adults. Although the ideal allergy test for identifying food antigens in EoE remains to be elucidated, the utility of food skin prick combined with atopy patch testing has been shown in large pediatric cohorts. By comparison, smaller, non-U.S. adult cohorts have not had similar results. Currently, a positive test on food allergy evaluation suggests a food trigger for EoE but does not substitute for biopsy based tissue evaluation following food removal and re-introduction. The higher rates of food anaphylaxis in children with EoE, potential loss of tolerance to IgE positive foods that can occur with food avoidance, and the high rates of other atopic diatheses in EoE subjects all support the evaluation of EoE subject by an allergist, consideration for allergy testing, and an integrated approach by allergists, gastroenterologists, and pathologists in EoE management.

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Food antigens and EoE pathogenesis
Eosinophilic esophagitis (EoE) is a clinicopathologic entity of increasing worldwide prevalence that affects both children and adults (1, 2). EoE is a chronic, immune, antigen mediated disorder with a pathogenesis akin to other allergic diseases such as asthma and eczema in which an antigen induces a cascade of Th2 interleukins and chemokines in addition to inflammatory cell infiltration (1, 3, 4). The diagnosis of EoE relies on the presence of a robust esophageal eosinophilia of ≥15 eosinophils per high power field which persists after a PPI trial (1). The process is frequently pan-esophageal and accompanied by histologic remodeling inclusive of submucosal fibrosis and angiogenesis which translates clinically into esophageal rigidity and dysmotility and symptoms of dysphagia (510). Important molecular factors for eosinophilia and remodeling include IL-5, -13, eotaxin-3, and TGFβ1 (3 5, 1114).

Food antigens clearly function as antigenic triggers for EoE induction and exacerbation in pediatric and adult populations (1519). In 1995, Kelley and Sampson postulated that acid resistant esophageal eosinophilia could be due to food antigen exposure in children. Based on this hypothesis, these investigators treated children with gastrointestinal symptoms and esophageal eosinophilia with amino acid formula. Following a minimum of 6 weeks of treatment, all of the children experienced resolution or improvement of symptoms with significant reductions in esophageal eosinophilia (17). Since then, these data have been validated at multiple centers. Indeed, amino acid formulas are one of the most effective EoE therapies with resolution rates often higher than 96% in children (16, 18, 20, 21). The removal of all food antigens from the adult diet is also effective in resolving EoE with improvements in endoscopic and histologic features in 72% of subjects following 4 weeks of treatment (22).

A second line of evidence in support of food antigens in the pathogenesis of EoE is the clinicopathologic response to specific food elimination in the form of empiric elimination diets (15, 16, 23, 24). Empiric elimination of specific food groups (milk, egg, soy, wheat, peanuts/tree nuts, fish/shellfish) is highly effective in controlling EoE associated symptoms, endoscopic abnormalities, and eosinophilia. In children and adults, the empiric elimination diet resolves EoE in over 60% of subjects (15, 16, 18, 25). Food antigen elimination can also resolve fibrosis, at least in children (26). As such this food elimination diet not only provides a therapeutic remedy in EoE, but also provides proof of concept that food antigens are EoE instigators. Further evidence for the sufficiency of food antigens in initiating EoE comes from experimental models in which both peanut and egg exposure can cause the accumulation of eosinophils in the murine esophagus (6, 27). In these animal model systems, food antigen exposure induces many features of EoE inclusive of basal cell proliferation, esophageal eosinophilia and mastocytosis, and lamina propria remodeling with fibrosis (6, 27).

From
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4048803/
10-02-2016, 09:07 AM   #4
my little penguin
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