Imagine that you are feeding your precious infant, and within a few hours of eating, he starts vomiting repetitively, becomes floppy and lethargic, and you need to go to the emergency department. Now imagine that this happens over and over. Each time your baby undergoes extensive testing for serious conditions like sepsis and intestinal obstruction, you are told the tests are normal, yet you know there is nothing normal about what your baby is experiencing. You follow up with your pediatrician and still have no answers about what is happening. How do you go about introducing new foods, and are you brave enough to try?
As an allergist, the above story is very familiar. While on paper this diagnosis may seem clear, in practice it often is not. Patients often have multiple episodes before the diagnosis is considered. This causes significant stress for families and often leads to many unnecessary diagnostic tests. It is important that we as a medical community raise awareness of food protein-induced enterocolitis syndrome (FPIES) to provide families timely diagnoses and guidance to reduce stress and improve care.
FPIES is well-described in this month’s In Brief, “Food Protein-Induced Enterocolitis.” FPIES is a non-IgE-mediated food allergy that is increasing in frequency, and the article states, “typically characterized by vomiting and diarrhea associated with allergen ingestion.” The number of foods associated with this disorder is also increasing. In the past, peanut was not often seen as an FPIES trigger in infants. Since we have encouraged early introduction of peanut, more cases of FPIES to peanut have been reported. FPIES was also thought to be a diagnosis of infancy, and now we are seeing FPIES in older children and adults. As such, we need to remember to consider this diagnosis in older individuals as well. As mentioned in the article, chronic FPIES in infants is most commonly due to milk and soy. Recently, however a report of chronic FPIES due to solid foods was described in a young adult.
Atypical FPIES occurs when an individual initially has a classic FPIES reaction and then develops specific IgE to that food as well. This occurs in about 25% of cases. When this happens, it is important to prescribe self-injectable epinephrine; the food challenge will be designed differently than a typical FPIES challenge.
FPIES reactions can be extraordinarily frightening for caregivers, especially when they lead to pallor and lethargy. When this occurs repeatedly and an association with food is established, caregivers may become fearful of introducing new foods to their child. This may lead to inadequate development of feeding skills, poor weight gain, and nutritional deficiencies. Parents want advice regarding how and when to introduce new foods. Parents also want to know how strict they need to be with respect to the spectrum of avoidance. Clear guidance and support is important in this process.
Studies have shown that FPIES, like other food allergies, can have a significantly negative impact on quality of life. A prompt diagnosis, a knowledgeable clinician, referral to feeding therapy, and ongoing support can ameliorate this negative effect. Families want to know when and if FPIES will resolve and how to keep their child safe. Unfortunately, the only way to know if this has resolved is by performing an oral food challenge. Parents are understandably often fearful to perform these food challenges, especially when the initial reaction was severe.
In addition, the challenges of day-to-day life are heightened due to the lack of community awareness of this condition. Many individuals working in childcare facilities and preschools do not have experience caring for children with FPIES. As the prevalence of FPIES increases in older children and in cases when resolution takes longer, this lack of awareness affects our school-aged children as well. Furthermore, there are regional differences in the most common foods causing FPIES. Families need to have data about the region in which they live and feed their children. Time to resolution of FPIES can depend on the foods involved, and this can be different depending on the country in which you live.
The underlying pathophysiology of FPIES is complex and poorly understood. The need to improve our understanding of disease mechanism cannot be overstated, and this past year the National Institutes of Health held an FPIES symposium to foster discussion towards these efforts. The first grant to study FPIES was also awarded and serves as an exciting first step toward progress for those affected by FPIES.