In case you read no further, say a little prayer or cross your fingers for Bubba this week, will you? She has her biggest food challenge to date this week – baked milk.
In case you’re unfamiliar with the nomenclature here is a brief overview:
Milk, like many foods, is comprised of multiple proteins. The main proteins are whey and casein. Whey proteins are not heat stable, meaning they break down under high heat, whereas casein proteins retain their allergenic properties even when heated. You can be allergic to one or both. Seventy to eighty percent of milk-allergic children are able to tolerate baked-milk. The inclusion of baked-milk into a child’s diet has nutritional, social, and potentially allergenic benefits. Studies show that children who can tolerate baked-milk and include it in their diets are more likely to outgrow their entire milk allergy and outgrow it at an earlier age. So how do you know if a food challenge for baked-milk might be appropriate?
Predicting Baked-Milk Challenge Outcomes
The decision to undergo a challenge should be under the supervision and with the advice of an allergist. Factors may include your child’s age, history of reactions, IgE blood levels, and skin prick test (SPT) results. For an extended discussion on the details of specificity v. sensitivity in the various testing methods for cow’s milk allergy, see this article. Interestingly, one study identified milk SPT wheal size as more predictive than casein-specific SPT wheal size or milk IgE levels. Those researchers suggested a milk wheal size of <12mm would be an appropriate indicator for clinical food challenge readiness. Other researchers demonstrated the utility of casein-specific IgE levels in predicting challenge outcomes. Specifically, a casein IgE level of <4.5 equals a 95% chance of passing and >20.2 IgE level equals a 95% chance of failure. In the past year, Bubba has dropped from a casein IgE of 5.41 down to 3.67. Finally, here is one additional article discussing readiness for an oral food challenge and contraindications.
The work of Dr. Nowak-Wegrzyn (and others) demonstrates: those children who can tolerate baked milk are more likely to outgrow their entire milk allergy and those who regularly ingest it are likely to do so at an accelerated rate (compared to those who strictly avoid all milk products). The immunological changes these children experience are similar to those kids with spontaneous resolution and who undergo milk oral immunotherapy (OIT). At-home baked-milk ‘therapy’ is easily implemented and is far less likely to be frought with the potential adverse effects of OIT.
Milk has been Bubba’s biggest kryptonite. She has had more anaphylactic reactions to it than to any of her other allergens. It was her first anaphylactic reaction (at 15mo) and her most recent (October 2014). If milk touches Bubba’s skin, she gets contact hives which thankfully resolve with simple skin washing. If she ingests milk, Bubba vomits immediately and violently. She continues vomiting even after the food has left her body. Her throat starts to swell, making her cough and her voice grow hoarse. Thank God for epinephrine.
Milk is everywhere, all the time. Pizza parties, ice cream parlors, grills laced with butter, powdery cheese dust snacks, squeeze tubes of yogurt, toddler sippy-cups, breads, chocolate, etc. It is her, and therefore my, nemesis. It sounds funny to say, but if Bubba could outgrow her milk allergy someday I feel like she would start to blend into the ever-growing group of kids with a nut allergy instead of existing in a daunting food-allergy world all her own. It seems like most kids these days have some friend with a peanut allergy. It is sadly becoming the new norm. So cross your fingers for her, for hope, and for progress in this long, long journey.