Allergy testing siblings: quick update

Here’s a brief overview of my children’s allergies. My son, D (now almost 3 ½) has a severe peanut allergy, plus asthma, eczema and various environmental allergies (cat, dog, grass and house dust mite). My daughter, C (almost 2), has no known allergies as yet, although following a recent bug she was prescribed a blue “reliever” inhaler and put on a daily dose of montelukast.

Last autumn, C began attending nursery one day a week. During an initial conversation with her room supervisor, it became clear that, even with my express permission, they could not use D’s medication on C, if she suffered her first allergic reaction whilst at nursery. If C suffered anaphylaxis, they would need to call an ambulance and wait for the paramedic to arrive to administer the adrenaline (see Isn’t it time UK nurseries and schools held unassigned EpiPens?).

D’s allergies, asthma and eczema put C in the higher risk bracket for peanut allergy (see Allergy testing siblings). According to a 2008 study, the fact D is peanut allergic means C, as his younger sibling, has a “12-fold increased risk for peanut allergy”.

The upshot? I was extremely keen to have C peanut allergy tested, so she could be prescribed her own emergency medication, if need be.

Obtaining a GP referral

At D’s last allergy appointment, I raised this with our allergy doctors and they agreed that C would be tested. However, I first needed a GP to refer her to the allergy clinic. So off I trotted to our doctors, expecting that I may need to plead for a referral. There was no begging required. The GP happily processed the referral and, earlier this month, we went to the hospital for C’s first allergy appointment.

D & Family, the day he was released from hospital

Skin prick test negative, as expected

I’m pleased to report that C skin prick tested negative for peanut (hurrah!). We discovered D’s peanut allergy when he had anaphylaxis when C was only 4 weeks’ old. Our house has been a nut free zone ever since and all of us have avoided eating nuts. So C has never even eaten anything which “may contain” nuts, let alone something that has nuts in the ingredients. Our allergists were therefore fully expecting C’s skin prick test to be negative.

According to Dr Andrew Clark (in a 2010 Q&A piece for Mumsnet), following a negative skin prick test result, there is a 95% chance that the sibling, who had never eaten peanut, would not react to eating it for the first time. So despite the negative result, it is still possible that C might react in years to come if she ever eats peanut.

What happens next?

Our hospital are now arranging for C to come in for a food challenge, where she will be fed peanut butter in increasing doses, to confirm she does not have an allergy.

I was relieved to hear that, if C passes the food challenge, our doctors would not then recommend that she should eat peanut on a regular basis. My understanding is that, if C passes the challenge, it would not be a case of her needing to maintain a “tolerance” to peanut. If she’s simply not allergic in the first place, she could then eat as much or as little peanut as she chooses.

Our doctor remarked that, if C sailed through the food challenge, I wouldn’t then, for example, have to take the same precautions for C at birthday parties, as I would for D. I hadn’t really considered that aspect before. Although I know that D will need to learn to be careful about what he eats and to always carry his medication, hopefully, growing up, he won’t be TOO aware of the precautions (and associated parental anxiety) that happen behind the scenes, as we prepare for school, play dates, parties, eating out, holidays and so on. However, the doctor’s passing comment brought it home to me for the first time how different it will be parenting each of them on the food front, going forward.

Update (April 2014): I’m very pleased to report that my daughter passed her peanut challenge and so has avoided having a peanut allergy like her big brother. See How peanut butter found its way back on my shopping list.

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