Risk Factors and Clinical Features in Cashew Nut Oral Food Challenges

Int Arch Allergy Immunol. 2018;175(1-2):99-106. doi: 10.1159/000486120. Epub 2018 Jan 18.

Abstract

Background: Cashew nuts (CN) are capable of causing severe allergic reactions. However, little has been reported about the details of CN oral food challenges (OFC).

Methods: CN-specific IgE (sIgE) levels were measured for 1 year in 66 patients who underwent an OFC with >3 g CN for diagnosis or confirmation of tolerance acquisition between June 2006 and August 2014. We retrospectively analyzed the OFC and patient background.

Results: The median (IQR) age of the 66 patients (48 boys/men and 18 girls/women) was 7.0 years (5.7-8.8). Twelve patients (18.2%) had a positive OFC result; 6 of 8 (75%) patients with a history of an immediate reaction to CN failed the OFC. Anaphylaxis was experienced by 5 of these 12 (42%) patients. A history of an immediate reaction to CN and the CN sIgE levels were significantly different for patients with a positive or negative OFC result (p < 0.01). Among patients without a previous immediate reaction to CN, the 95% positive predictive value (PPV) for the CN sIgE level for a positive OFC result was 66.1 kUA/L.

Conclusions: A history of an immediate reaction to CN and high CN sIgE were risk factors for a positive OFC result. The number of positive OFC results was relatively low, but there was a high probability of anaphylaxis. We should consider the indication of OFC carefully for patients with a history of immediate reactions to CN and avoid OFC for patients without such a history whose CN sIgE values are >66.1 kUA/L (95% PPV).

Keywords: Allergic reaction; Allergy; Cashew nut; Oral food challenge; Risk factors.

MeSH terms

  • Administration, Oral
  • Adolescent
  • Adult
  • Allergens / immunology
  • Anacardium / immunology
  • Anaphylaxis / etiology
  • Anaphylaxis / prevention & control*
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Immunization / adverse effects*
  • Immunoglobulin E / blood
  • Male
  • Medical History Taking
  • Nut Hypersensitivity / complications
  • Nut Hypersensitivity / diagnosis*
  • Patient Selection
  • Recurrence
  • Retrospective Studies
  • Risk Factors
  • Young Adult

Substances

  • Allergens
  • Immunoglobulin E