The Mother of All Allergies

The title of this post is taken from the article in the Journal of Pediatrics (2003) by Philip E. Putnam, where he suggests we simply call non-IgE mediated food allergies by a new name, reflective of it's impact on the lives of families: The Mother of All Allergies. I'm structuring this post as a Q&A, using salient quotes from the article to provide a answers to frequently asked questions, because, although it's from 2003, it still holds true today. 

Most people are familiar with immediate hypersensitivity, oral allergy syndrome, celiac disease. There are clear and timely symptoms for these conditions such as hives, anaphlylaxis, elevated serum IgE, postive skin prick and radioallergosorbent tests. But, Putnam contends, immunologic reactions to multiple foods can present in more subtle fashion and someone might exhibit a broader variety of symptoms. Something like FPIES is non IgE-mediated and, in addition to the acute, but delayed symptoms of vomiting and diarrhea, other more subtle symptoms might also occur (for example, atopic symptoms such as eczema).

So, what foods can a baby with FPIES safely eat? Actually, all food contain proteins so no food, herb, even medicine or food additive are safe unless trialed first. Putnam describes the difficulties in even identifying the trigger foods when skin prick testing is negative and reactions are delayed. "In the absence of perfect testing, double-blind placebo-controlled food challenges (DBPCFC) are necessary for confirmation of a relationship between the symptom and ingestion of the food. For delayed reactions, DBPCFC are reliable when clearly positive or negative, but when the symptoms are non-specific (sleep disturbance in a toddler, for example) they are fraught with the vagaries of the subjectivity beast. Because they are time-consuming and produce illness when a reaction develops, the challenge for us is to develop accurate, reproducible, noninvasive means for identifying the offending foods."

Why are we hearing more about such conditions? Putnam notes that there seems to be an increasing population of children who are failing to develop oral tolerance, although why this is, is yet unknown. There are a lot of opinions on the web about the proliferation of GMO foods and the impact of poor microbiomes on our gut health but nothing has been proven, because few scientific studies have been undertaken.

But, your baby seems fine. Yes, when the offending food is not in their system, the baby does seem fine. However, their GI tracts might not be fine. Putnam describes a study wherein "careful examination of other immune markers including IgG subclass levels and quantitation of lymphocyte subpopulations revealed subtle deviation from normal" and that "mild enteropathy resulting from immune reactions to food was only discovered on morphometric analysis of duodenal biopsies, many after a provisional diagnosis of “normal” had been entertained". 

But, it's easy once you have a doctor on board, right? Putnam goes on the describe the nightmare some families find themselves in. "The frustration of families in those situations should not be underestimated. Months and years of delay, denial, and barking up the wrong tree take an enormous emotional toll on the family while perpetuating the damage to the baby. It might be easy to see how a parent insistent on additional testing for fairly nonspecific symptoms might eventually be accused of Munchausen's syndrome by proxy, but the fact that 5 of 77 families in this cohort were so reproached despite other objective and suggestive findings in their children is shameful. At the same time, it is not surprising that these families fail to successfully navigate the subspecialty labyrinth. The gastroenterologist did the endoscopy and didn't see much, the biopsy results were underwhelming to the pathologist, and the allergist said the child wasn't allergic because the skin tests were negative. Random elimination of foods didn't help. The child is still sick. Now what? Of course, there is no simple solution. When all indications point to food allergy, an elemental diet trial becomes both diagnostic and therapeutic when successfully completed, which is no small task after infancy."

So, what is daily life like for a baby with a severe case of FPIES? For babies who have reacted to everything they have been given, "continuing food challenges in the face of repeated failure is emotionally taxing and, if not carefully done, commits the child to perpetual illness during the failed search for something to eat." As a parent, you live each day in fear and guilt, for the things you must feed your child, are the very things that make them ill.

But, he'll outgrow it, right? Many children do outgrow FPIES, but "for children who fail to develop significant oral tolerance, school age is particularly difficult. Food as nutrition, party fare, treat, snack, prize, reward, or commercial advertisement is everywhere. For the child whose backpack contains an infusion pump and formula instead of books, food outside the parents' observation represents a challenge, potential threat, or opportunity to cheat. The presence of food in the classroom magnifies the difference between the hypersensitive child and those who eat, and increases the psychologic impact of the disorder." Mom-designed shirts such as the one pictured might be bought with good intentions (to save your child's life!), but may also serve as indicators of how different your child is and we all know how children react to others who are different.

So, can you give him some special formula that doesn't contain protein? For some families who have no/few safe foods, elemental formulas, whose proteins are already broken down into free amino acids, are the only legitimate option to ensure their children are nourished. However, long term use can pose it's own problems. "Exclusive use of formula from infancy forestalls normal acquisition of oromotor skills, such that when food trials are proposed, the child may be developmentally unprepared to accept the new food, irrespective of its immunologic importance. Gagging, vomiting, and overt refusal confound the interpretation of immune tolerance. In addition, with prolonged use, many children simply refuse to drink enough formula to meet their nutritional requirements and thus require tube feeding. The cost of elemental formulas is prohibitive for most families. The constant battle to obtain insurance compensation over insipid arguments posed by companies prepared only to preserve their fiscal security has forced families to engage media attention or legal representation..."

Certainly, more work on non-IgE mediated allergies needs to be undertaken. As we see more and more cases getting diagnosed, it is my hope that the importance of research and understanding will be front and centre in the minds of doctors and the public when supporting families with children who have these conditions.