Diet Therapy, Single and Multiple
To date, nobody doubts that the culprit food has to be always and strictly eliminated from the patient's diet up to the spontaneous achievement of tolerance. This is a difference between FPIES and IgE-mediated FAs: the management of FPIES does not provide, as happens for some common IgE-mediated FAs, the possibility of initiating oral immunotherapy (OIT) in order to actively induce tolerance or at least desensitization. OIT was never performed for FPIES, as spontaneous tolerance is achieved relatively soon, usually within the first 5 years of life: it's not worth exposing patients to the risks of OIT for such a short wait. So, patients cannot ingest even small amounts of culprit food, as the minimum quantity which can cause an acute episode is still unknown, and it's very difficult to obtain this information due to the latency period of the symptoms; the patient always has the time to finish the meal before symptoms arise. We also do not know if small and frequently ingested amounts of food can cause chronic FPIES. So in case of FPIES, diet concerning the culprit food must be very strict and has no alternative.
Moreover, Sicherer has also proposed the elimination from the diet of other foods in addition to the culprit. In fact, this author suggests, in case of CM FPIES, to avoid ingesting soy and cereals and to delay the introduction of other solid foods, at least until the baby is one year old. In case of FPIES induced by solid food, he proposes avoiding the ingestion of cow milk, cereals, legumes and poultry, at least until the baby is 1-year-old. Of course, the preventive diet will be implemented only if the foods in question, at the time of diagnosis of FPIES, have not already been eaten without problems by the child. The suggestion is born from the observation of a clinical reactivity to these foods in children with CM FPIES or solid food FPIES in the USA in a series composed of 30−50 individuals.[21,22] However, Sicherer precises: "These strategies represent only one of many possible courses of action and would require alterations in approach depending on numerous factors, including severity of previous reactions, clinical judgment, nutritional needs and patient preferences. Foods that are clinically tolerated should not be removed from the diet". When the Italian, Australian and Israeli clinical series (a little less than 150 cases total) were published, it was observed that the occurrence of FPIES caused by many different foods in the same child ('multiple FPIES') was infrequent; in our experience this event happens at most in 2% of cases. In light of this recent information, we think that the probability of a multiple FPIES is too low to suggest multiple dietary restrictions for all children with FPIES to their debut.
Expert Rev Clin Immunol. 2013;9(8):707-715. © 2013 Expert Reviews Ltd.