Kirsi M. Järvinen


Curr Opin Allergy Clin Immunol. 2011;11(3):255-261. 

In This Article

How Does Food-induced Anaphylaxis Present?

The majority of reactions manifest within 1 h of exposure, but the onset of symptoms may occur a few hours after exposure to the food allergen, possibly related to a less severe reaction or delayed absorption of the food.[3] The symptoms are most commonly seen in the skin (urticaria, angioedema, pruritus, flushing) and respiratory tract (cough, difficulty breathing, wheezing) in about 80% of cases[4] (Table 1).[12] The cardiovascular system is less often affected than in anaphylaxis of other causes,[13] especially in children.[4]

The clinical presentation including the onset of symptoms, clinical severity, and sequence of symptom progression can differ between individuals and between reactions in the same individual and is likely dependent on the amount of food ingested, consumption of food to an empty vs. full stomach, concurrent illness, exercise, consumption of alcohol or medications, menstruation, among others.[14,15] Exercise and intake of nonsteroidal medications increase intestinal uptake of food allergens.[16] Food-dependent, exercise-induced anaphylaxis occurs when ingestion of food occurs within 2–4 h of exercise. Symptoms do not occur in the absence of exercise.

Features of anaphylaxis differ between children and adults.[17] Whereas adults reported severe symptoms, including cardiovascular collapse more often, severe abdominal pain, hives, rhinitis, conjunctivitis, flushing was reported more often in children.[18] Among the pediatric population, hives and vomiting were more commonly documented in infants, and wheezing and stridor more frequently in preschool-aged children.[19•] Adolescents reported subjective symptoms such as trouble swallowing and difficulty breathing more often. The rate of anaphylaxis in infants is unknown, but it is likely underdiagnosed because the presentation may be atypical and nonspecific in infants including lethargy, cyanosis, fussing, irritability, and seizures, and some signs are otherwise common in infants (drowsiness, regurgitation).[20] Their inability to report subjective symptoms and infrequent blood pressure measurements[19•] further complicate diagnosis.

Late-phase reactions typically develop within 8 h of resolution of the initial reaction but may occur up to 72 h later.[21] These late phase reactions have been reported in 3–20% of anaphylactic reactions of all causes[22,23] but in only 2% of anaphylaxis induced by foods during in-patient oral food challenges.[24•] Previous studies have suggested orally administered allergen, delayed onset of initial symptoms (>30 min), prior β-blockade, and a delay in the administration, an inadequate amount or the requirement of larger doses of epinephrine as risk factors.[22] The mechanisms of biphasic reactions are largely unknown.[25]


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