0521779407-07 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:10
Food Allergies 583and/or respiratory tract allergy, allergic eosinophilic gastroenteritis
in patients with asthma or allergic rhinitis
■History of improvement of symptoms after exclusion diet
■History of negative GI diagnostic work-up
Signs & Symptoms
■Immediate – Type I IgE mediated hypersensitivity reaction (within
minutes after ingestion)
■Anaphylaxis (generalized systemic shock)
■Postprandial exercise-induced anaphylaxis
■Itching, eczema, urticaria, dermatitis (skin)
■Rhinitis, laryngeal edema, bronchospasm, nasal congestion (respi-
ratory)
■Angioedema of lips, tongue, palate, throat, pruritis, rapid onset and
resolution (oral allergy syndrome)
■Vomiting, abdominal pain and cramping, bloating, GI bleed, abdom-
inal distention, diarrhea, onset within minutes to 1 hour of ingesting
suspected food allergen (gastrointestinal anaphylaxis)
■Postprandial nausea, vomiting, abdominal pain, diarrhea, steat-
orrhea, weight loss (allergic eosinophilic gastroenteritis -mucosal
form)
■Delayed – Type IV cell-mediated reaction (can occur hours to days
post ingestion of suspected food allergen)
■Non IgE mediated syndromes: celiac disease, dermatitis herpeti-
formis, most cases of cow’s milk allergytests
Basic Studies:
■Serum – IgE, eosinophils
■Stool – IgE, eosinophils
Specific diagnostic Tests: if IgE-mediated disorder is suspected
■Skin test (prick/puncture) with fresh food or commercial extract; (+)
test=wheal >3 mm in diameter than control
■In vitro test (RAST=radioallergosorbent test) – used if substan-
tial risk of anaphylaxis exists, semiquantitative measure of allergen
specific
■IgE in serum : Elisa or basophil histamine release assay
■Elimination diet for 1–2 weeks
■Food challenge: open single blinded vs double blinded placebo con-
trolled oral food challenge (gold standard)
■Endoscopic biopsy helps document allergic eosinophilic gastroen-
teritis (eosinophilic infiltrate) vs non IgE-mediated celiac sprue