food challenge and immunocap testing?

[evergreenmom]

I am looking for advice regarding my nearly six year old son. He developed a sensitivity to peanuts at age 3 1/2, had a reaction and was confirmed with skin test w/16mm weal. No reactions since due to fairly extreme level of caution/paranoia on my part. Recently he had blood work done( RAST I think) and his peanut IGe was 0.37 and overall IGe of 280. His allergist wants to do an in office skin test followed immediately (if skin looks good) by an oral challenge to peanut butter. I am feeling very worried about all of this and have never looked in to it much in the past because I didn't want to get my hopes up that he might outgrow his PA.

's:
a. Should I request an immunocap or Uknow peanut test be performed first to be better informed as to whether or not food challenge is safe? Also, is one test better or cheaper or easier than the other or are they the same???
b. Should the scratch test be done on a prior occasion to the oral challenge?
c. Should oral challenge be completed in office or hospital setting?
d. What happens if my son won't cooperate and ingest (evil/frightening/disgusting) peanuts? He never liked taste of PN as toddler probably because he sensed mild sensitivity which later became more severe after accidental ingestion of peanuts hidden as "nu nuts" in "praline" ice cream
e. Will we have to continue to feed him peanuts if he passes the oral challenge?
f. For how long after passing a challenge does one still need to carry an epi/be concerned about re-sensitizing?

What else should I be considering?

Thanks in advance for your support, Kristin

[booandbrimom]

Well...here are my opinions:

- Immunocap: this is an expensive test. I love to recommend it to parents who want the extra assurance (or push) to do a challenge. But, if you're willing to do the challenge based on the regular testing, you should save your money and just do it. At the end of the component test, you'll still have to do a challenge, so there's no real advantage other than more certainty of passing. If your son has had a reaction, you already know he was/is allergic.

- RAST/scratch testing is usually done before a challenge. If your doctor is willing to do it same day, it saves you a visit. Just be prepared for disappointment because a) scratch tests can stay positive longer than RAST, and b) 16mm is pretty big.

- An oral challenge for peanut should be done at the hospital IMHO. My son has done many challenges in our doctor's office (which is adjacent, but not in the hospital), but I would not allow him to do peanut there.

- Peanuts can be ground up and put in chocolate pudding. You usually bring your own food for a challenge - just grind the peanuts and bring (safe) chocolate pudding with you. 

- Most doctors do recommend keeping peanut in the diet to prevent re-sensitization. Of course, they may have no idea what they are doing. No one knows why kids outgrow allergies and what keeps their bodies tolerant. I say cross the bridge when you get there. And, again, something like chocolate pudding is very good at masking the taste if you do decide it's necessary.

- I believe most doctors recommend at least a year or two of continuing to carry the Epi. But, considering that a good percentage of peanut-allergic individuals don't carry one at ALL, I would say it's your call.

Good luck!

[booandbrimom]

P.S. uKnow is the parent-friendly branded version of the peanut-specific Immunocap component test. Your doctor may have an account with the Pirl lab that does component testing, in which case he or she can order it. Otherwise, I believe the uKnow lets you use a local lab to do the blood draw and then it gets sent to them. 

http://www.pirllab.com/lab/pirl_science.html

[Mfamom]

we had similar situation.  We had ana reaction etc.  total avoidance for years with a few contact reactions.  we did see a change in ds overall in his sensitivity (improvement in eczema, overall allergic symptoms improved over time). 
Drs would not challenge (local allergist and Dr. Sicherer) as we had a low rast, but big wheal on skin test plus past ana reaction.
Additionally, my ds was terrified to do a challenge because he remembers his first reaction.
So, doing the uknow ahead of time gave us the information we needed to realize that he was in the mild category and unlikely to have much risk during a food challenge. 
The interesting thing too is that he had a spt less than one year ago with that same 17 mm wheal (so false positive)
IMHO, the uknow is well worth it!  Our insurance paid for it, so total no brainer.  (less a minimal copay)
we just challenged about a month ago.  We did it at the office which as booandbrimom said is a bit scary.  We were within 1/4mile of major hospital and dr would not do challenge there, so we did in office. 
We were told to bring Straight up peanut butter, I think every doctor is different with their opinions about mixing foods during a challenge.  He said PB only. 

[evergreenmom]

Thanks for the comments...  I will ask Dr about doing a component test, I just think I will feel more comfortable come food challenge day if I have additional reassurance that the risk is mild and if the risk is not mild then we won't do it.

Mfamom- what are your current doctor orders regarding eating peanuts and carrying epi pens?

Thanks so much for the input!

[Mfamom]

Honestly, the allergist told ds you don't need it anymore (meaning the epi pen) and did not give advice on how much pn to eat weekly/daily etc. told him to work his way up to eating it a few times a week, but didn't push it or make a big deal about it.

Ds has been keeping his auvi q with him and he really dislikes pb, but I'm asking him to eat it at least weekly.  I have a bag of pn m&m in the cabinet and I'm trying to get him to eat a couple every day.
He ate chinese food the other night for the first time and he had a Blizzard from DQ on sunday.  i think he added reeces pieces to it. 

[Macabre]

Mfamom when do you plan on changing the 504? 

oh, well holy crap.  Small town, small school....the nurse found out "through the grapevine" and she called me and verified that he passed the challenge.  I received a letter a week later stating that as per conversation, accommodations are no longer necessary.  Nurse agreed to keep his epi pen the remainder of the year and acknowledged that if something went wrong she would not rule out PA and give epi.
Honestly, I don't have the energy to deal with school anymore

[evergreenmom]

I had read somewhere(sorry I forget where ) to be prepared to carry epi for at least one year possibly two after a successful food challenge. I had also read to ingest peanut at least weekly, some study showed one a month as being not enough and subjects re-sensitized,m again sorry, can't recall where I read this. I am going crazy researching all things allergy at the moment and it's hard to keep everything straight;o) 

[LinksEtc]

I had read somewhere(sorry I forget where ) to be prepared to carry epi for at least one year possibly two after a successful food challenge.

The allergists I've seen have disagreed on this point .... Some say no need to carry if the person passed the challenge and has no other allergies ... Some say to continue to carry for a year or so.

My non-medical, non-expert opinion is that I prefer the approach of carrying for a while after a passed challenge. 

If the challenge is not a completely clean pass (some questionable/mild subjective symptoms or mild objective ones), great caution should be taken and I would definitely want to continue to have epi.  In those cases, a repeat (often double-blind) challenge might be a good idea to rule out a false pass.


"OUTGROWN" A PEANUT ALLERGY? EAT MORE PEANUTS!"
http://www.hopkinsmedicine.org/press_releases/2004/11_09a_04.html

Wood also recommends that those children who do eat concentrated peanut products frequently carry epinephrine injections for at least one year after passing an oral food challenge

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I had also read to ingest peanut at least weekly, some study showed one a month as being not enough and subjects re-sensitized,m again sorry, can't recall where I read this.

The above Hopkins link also mentions this recurrence issue.

Here is another example:
http://www.chop.edu/service/allergy/preparing-for-your-childs-visit/food-challenge.html

We therefore recommend that your child keep the specific food in his diet about three times per week. Recurrence of allergy has infrequently been reported, and these episodes were associated with infrequent ingestion or avoidance of peanut.

You can discuss your concerns/questions/preferences about challenges with your allergist before making a decision whether you want to challenge.  You can ask what his/her recommendations would be following a passed challenge.


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I am going crazy researching all things allergy at the moment and it's hard to keep everything straight;o)

 

I'd recommend concentrating on the basics.  Don't drive yourself nuts trying to understand everything all at once ... deeper knowledge usually comes with time.  This is a nice thread that I would recommend those new to our group read through.

What would you tell someone new to LTFA?


 

[twinturbo]

What's the code for the generic form of Uknow? The peanut component?

This? 91681: Peanut Component Panel

[evergreenmom]

see my other thread about borderline results...

[Mamabear]

I know this thread is kind of old now but I wanted to hear from the original mama. My 20 mo old son has a ara h2 peanut component test result of .42. This is obviously extremely low, but... We got this test done after an anaphalactic reaction to ingesting peanuts. I just wanted to caution anyone that may be considering a food challenge with such a low number. Ara h2 is consistently associated with anaphalaxis.
I get such mixed answers from asking this? But I just really would like to know if anyone has heard of outgrowing ara h2. I know the component test is rather new but there must be some data available?

[CMdeux]

Mamabear, I don't know the answer to your specific query-- but we've not done component testing for the very reason that your post illuminates.

What would we do if the ara h2 number wasn't significantly elevated??  My daughter has had anaphylaxis that nearly killed her...  more than once.

So I am not really in need of the information that the uKnow component test would tell us.  It could only do one of two things:  a) tell us what we already know, or (worse) b) tell us something that makes no sense in light of what we know.

People like us don't tend to be included in the stats for the component testing.  That is, we already know that our kids are anaphylaxers, and we don't need a test to tell us so.  Ergo, nobody really knows whether or not component testing show all of that population to be represented well with elevated ara h2 values or not.  My guess is that not all of them do have elevated ara h2.  In fact, it may well be that anaphylaxing is only loosely tied to particular proteins... and that people with moderate thresholds (and therefore those lacking florid reaction history-- those with super-low thresholds tend to KNOW that they are allergic via anaphylaxis pretty early) are the ones being captured with component testing.