Skin prick test +ve does not always mean you are allergic

[sagarika]

I would like to know your views re: skin prick tests. My ds(15 mo) is allergic to milk, egg, nuts,wheat, pulses(possibly peas), chickpeas , corn and tomatoes. We have never fed him eggs and nuts. We were told he is allergic to them as his skin prick test came positive. He however had bad eczema when I was eating eggs and nuts(as I didn't know about his allergies then). I am still breast feeding. A friend of mine told me that she knows someone who had similar skin prick test results to eggs and nuts but can eat them without any problem. I gave also read on the thread started by garliclover here re: dcs allergies that a dc showed positive skin prick test to peanuts but can eat them without any problem. So, is it possible that my ds might not be allergic to them. Pls advise

Who/where/how was the testing carried out?

well he has eaten those foods, via your breast milk, and if he has ezcema, exposure can arrive via the skin.

immunologists are the ones who conclude if your childs allergic or potenitally allergic, thats why we need them!

Those tests were carried out by paediatric allergy specialists in a London hospital . Since these tests came positive we were asked to avoid them in his as well as my diet. He had bad eczema when I was eating everything so I can't really tell whether it was because of nuts or eggs or other things. He still has mild ecEma despite strict dietary exclusion in both our diets. Immunologists??? I have never seen one. Are allergy specialists the same? Sorry if I sound daft!

He will have other atopic diseases like ezcema as he is an allergic person, and it sounds like you are in the right place doc wise, paed allergy specialists in a allergy clinic are usually immunologists!

false positives and negatives are part of testing , but thats why you need medical advice, with his reaction history, or not, his other atopic diseases, and general health, plus family history of atopic disease.

my son is at a london hospital as well!

Eragon, it feels so awful.when I was growing up I could eat anything and enjoy any food but my son is so allergic and potentially asthmatic, like you said. It kills me to see him like this. There's not much variety in the food that he eats. I hope and pray that he grows out of some of his allergies if not all.
My son's being followed up at St Marys Paddington allergy clinic.

my son also has positive skin prick testing to many foods - he can still eat them and shows no outward physical sign ie facial swelling, lips, difficulty breathing. The positive skin prick is part of his wide ranging allergy problems. Google it and you will see that many people with positive skin prick tests have no problem and no reaction when eating that particular food - however, that may not be the case for your baby! Look up IgE mediated allergies - that might help too.

well, during the early years of our allergic kids life they know no different, they have always been used to not eating certian foods. Of course as they grow older they are more aware, but as teens dont want others to know!

I try and think that we are lucky really , our son can run, walk etc, and though aviodance lives a normal life. I totally expect him to do the normal things other people do if he wants ! However there are other conditions that small children have that are very serious and will hamper life considerably.

on the positive note, our family eat better, and our son unlike the non food allergic ,doesnt have such a great focus on food to enjoy himself.

my son has been at st marys since he was 18months old, and is now a teenager. prof warner is our fab doc!

and on the subject of testing, reaction history is a huge factor in choosing which foods to test for. random testing of huge amount of different foods, eaten without reactions are a total waste of time, effort and money!

false positives and negatives are part of any form of testing and need to be taken in to account with other factors by allergy docs.

I don't know as have never had skin prick for DS but his RAST's are negative to things he reacts too.

dd4 has had RAST amd skin prick testing. with rast testing she came up negative to milk and eggs. so we went ahead with food challenges in hospital setting. she did not get past stage 1 (egg applied to cheek, milk applied to chin, 2 seperate appointments several months apart for these). so at next appointment we decided to go with skin prick tests instead. these came up as strong positives to milk, eggs and peanuts (nut mixes had shown up in rast testing).

so in dd4 case, skin prick testing is more accruate for her.

I understand what you are saying eragon. But introducing a new food in his diet can be so stressful, not knowing how he will react to it. And everytime he scratches a bit more than usual I start worrying whether it's the food or something he touched or is it because someone kissed him after having a yoghurt drink(it has happened to him before). It could be anything. Not knowing for sure is what I find frustrating. It's like walking in a mind field.

Wow your son's a teenager now. Has he grown out of some allergies??My ds has a long way to go...

Thanks everyone for your responses. I do understand that skin prick test alone is not conclusive or diagnostic in any way and that there are so many other factors that we need to look at.

Just a quick question. Has anyone's dc ever reacted to nutramigen. My ds's eczema seemed to have flared up since he's been on it. I have stopped giving it to him for 2 days now and his skin is much better. Is it possible that he might be reacting to it.

yes it's possible I'm sure. I'm sure someone here has said their DC has reacted to it before.

DD tried a sip of nutramigen at 10 months and had immediate hives all over and a bit of swelling even with us giving piriton straight away it was horrid (I'd felt really bullied into it by HV who said I was ridiculous thinking it might not be okay for her). I think some people only react to intact proteins but some react to the traces of broken proteins in nutramigen. I guess it's like some folk react to the dairy that comes through breastfeeding and how a lot of folk are okay with well cooked egg but some react to that too (DD does).

It could be anything. Not knowing for sure is what I find frustrating - I totally agree!

Yep, I think children that are very sensitive to CMP still react to nutramigen so definitely request neocate from your GP. They are often reluctant to prescribe it at first due to the cost but just push for it.

I think it was my post on the other thread that you were referring to - my DD can eat peanuts despite having +ve skin prick HOWEVER she's certainly not as atopic as your DS by the sounds of it (only allergic to dairy, eggs and tree nuts and no eczema/asthma). I spoke to my DDs consultant before I tried her on peanut and rubbed on arm, cheek, lip etc before I actually let her consume any (she reacts, with hives, to all her other allergens on touch). It was pretty nerve wracking to be honest. I'm sorry if I've made you doubt yourself.

If I were you I would avoid anything your DS has had +ve skin prick results to until you see your consultant.

I tried neocate when he was 5 months but he vomited it out everytime I gave it to him(twice or thrice) because of the taste. I am seeing the consultant next week. Will talk to her about prescribing neocate again. He did take nutramigen so hopefully he will take neocate as well. I wouldn't try him on any food he could be potentially allergic to without consulting his consultant of course. Thanks everyone so much, you make me feel hopeful..I hope my little one grows stronger each day.....

Yes, he will grow stronger each day with a mum as devoted and careful as you! I'm still finding my way with DS at 19mo, and sometimes I feel totally overwhelmed but those times are becoming less frequent now that DS is being seen regularly by a consultant, the docs are on our side, and I have a few meals stocked in the freezer. I hope your appointment next week is helpful, and fingers crossed for the neocate!

Thanks garliclover. Mumsnet has been a pillar of strength!!!

Dairy allergic DS was allergic to Nutramigen, it still contains CMP.

Just to let you all knOw that the appt went ok. The consultahat aid that it is possible for cmp allergic children to react to nutramigen aa due to cross contamination. He's now prescribed neocate. one thing that bugs me is that they do not provide a prescription for the hospital , we have to get it from the gp. Which takes 2-3 days and considering the weekend its going to be longer than that!!!!!

Although my little one's eczema is better his face has never been clear I have been using steroid off and on. This is another thing that I feel terrible about. We Hv now been prescribed a non steroidal ointment which we can use for 6 weeks and apparently it works! But first we were advised to clear his skin completely with steroids again. It's agonising ...But i hope it works this time.

Sorry about the typo "consultant said that"

If you're really worried you can buy it over the counter in the chemist.