Multiple Food Allergy Oral Immunotherapy (OIT)
Dr. Kari Nadeau discussed Multiple Food Allergy Oral Immunotherapy (OIT).
About 30% of children have multiple food allergies. Although OIT has shown some success with individual food allergy situations it is not normally done with multiple antigens.
There is 1 emergency room visit every 3 minutes for food allergy reactions in the U.S.
Dr Nadeau's group at Stanford is using Xolair as a tool to be protected during oral immunotherapy. Induction with Xolair should be done 8 weeks prior to induction of OIT. Dr Nadeau has 43 patients enrolled in multi-antigen OIT with Xolair. Omalizumab coverage in the study was for 16 weeks. Nadeau's dosing of Xolair in her OIT study (given in hope of protection against reactions) was same as product monograph for asthma. She did not observe any eosinophilic esophagitis in her OIT trial, unlike other studies.
54-80% of patients enrolled in the studies had some form of reaction during the OIT procedure. During OIT patients are requested to lower their allergen food dose by half if they have a virus to reduce reaction rate. Dr. Nadeau decreased OIT dose by half in girls who underwent menarche during the study as this was previously shown to be a risk for reactions. Food doses are reduced by half during OIT in the protocol during menstruation.
Most patients were able to get to 300 mg doses of each of their food allergens: equal to small exposures, with many getting to 4000 mg. OIT with multiple food allergies is still experimental and off label with Xolair at present time.
Egg allergy and baked egg challenges
Dr. Edmond Chan discussed baked egg challenge studies.
Up to 70-80% of egg-allergic children will tolerate extensively heated (baked) egg (Bartnikas in JACI). Can we predict the 20-30% who won't?
Oral Food Challenges (click to enlarge the diagram).
There is a larger SPT wheal diameter and more additional food allergies in those who fail a baked egg challenge. A negative SPT to the baked egg preparation has a 95% NPV, but there was anaphylaxis in one patient (Kim study in AACI).
A recent Boston study showed that 83% of egg-allergic children were baked egg tolerant, but 2 there were cases of anaphylaxis requiring Epi (not predictable by SPT or sIgE). sIgE to ovomucoid is not superior to egg white testing in predicting tolerance to baked egg.
In a retrospective study of 100 baked egg OFC, 66% passed, again not predicted by SPT or sIgE. A recent review (Peters, JACI 2013) showed that SPT and sIgE are not good predictors of baked egg challenge outcome.
The data remains conflicting as to what predictive tests will, in the end, predict success in baked egg challenges. It appears best to discuss risks/potential benefits with parents and proceed as per their comfort level.
Those children able to tolerate baked egg appear to "outgrow" egg allergy earlier, however it is not clear if this is therapeutic.
Twitter summary made possible by @IgECPD @allergydoc4kidz @DrAnneEllis
Three allergists did a great job posting updates from the 2013 meeting of the Canadian Society of Allergy and Clinical Immunology (#CSACI): @IgECPD @allergydoc4kidz @DrAnneEllis. Compared to year 2011, this represents 300% growth in Twitter use by the Canadian allergists (from one to three participants, stable since 2012.
For comparison, here are the tweets from the previous #CSACI meetings: http://allergynotes.blogspot.com/search/label/CSACI
Sign up for 2014 #AAAAI Twitter list and meeting of tweeting allergists in real life (tweetup)
The AAAAI has the advantage of a larger membership base compared to #CSACI and not surprisingly ten times more allergists (30) posted Twitter updates from the 2012 #AAAAI meeting. The AAAAI is now on Twitter at @AAAAI_org
This is a list of the allergists who are planning to use Twitter to post updates from the 2014 #AAAAI meeting. The list is open for edit, please feel free to add your own info.
The list shows the availability of the allergists by date and if they are planning to attend a tweetup (meeting of people who use Twitter or are following the tweets). See you at 2014 #AAAAI meeting in sunny San Diego!