100492 - Anaphylaxis from wheat

IgE-mediated wheat allergy typically develops after respiratory sensitization to pollens, with food reactions appearing later in childhood, often associated with lipid transfer proteins (LTP). Primary sensitization through ingestion in infants is considered uncommon.

We report the case of an infant younger than one year who developed a severe immediate allergic reaction following the introduction of a gluten-containing cereal product (SMILEAT® 7 Cereals). The product consisted of 99.7% cereals, including wheat flour, whole wheat flour, whole rye flour, whole spelt flour, whole oat flour, corn flour, rice flour, and quinoa flour, with added vitamin B1 (thiamine mononitrate). Approximately 10 minutes after ingestion, the patient developed rapidly progressive generalized erythema and urticaria lasting around 30 minutes, without vomiting. Upon arrival at the emergency department, the patient presented with oxygen saturation of 93%, respiratory distress with stridor and cough, marked irritability, and generalized edema with urticarial lesions. Treatment required two doses of adrenaline (150 mcg; one intramuscular and one intravenous), intravenous methylprednisolone, and supplemental oxygen via nasal cannula. 

Serum tryptase during the episode was elevated at 12.70 mcg/L, compared with a baseline level of 4.60 mcg/L. Specific IgE testing showed elevated levels to wheat (8.97 kUA/L) and oat (1.35 kUA/L). Prior to this episode, the patient had tolerated occasional isolated ingestion of small amounts of bread or breadsticks

This case highlights an early-onset, severe IgE-mediated reaction to wheat occurring before one year of age, suggesting primary sensitization through oral exposure rather than the more typical respiratory route. The early age of presentation and ingestion-based sensitization are noteworthy and raise the possibility of a non-classical sensitization pathway. The specific molecular component involved has not yet been identified. This case underscores the need to consider primary food sensitization even in very young infants and contributes to the understanding of early wheat allergy pathogenesis.