Background Food challenges are the gold standard for diagnosing food allergies.

Aim To identify risk factors that would suggest an increased risk of severe reaction requiring IM adrenaline at food challenge.

Method Retrospective review of 140 consecutive food challenges carried out at Cork University Hospital.

Results In total 140 food challenges were reviewed involving 115 children. 59/140 (42%) of food challenges were positive. 73/140 (52%) were negative. 117 food challenges were open, 2 single blind and 21 double blind. 5 patients refused challenge. 3 food challenges were inconclusive. 4 children (3%) (2 peanut and 2 egg) required IM adrenaline.

Mean maximum wheal diameter for all children was 3.2 mm, for children with positive food challenge 3.17 mm and children requiring IM adrenaline 4 mm. Mean specific IgE for all patients was 8.38 (range 0 to 100). Mean specific IgE for patients with a positive food challenge was 12.38 (range 0 to 100). Mean specific IgE for patients requiring IM adrenaline was 16.5 (range 4.68–40).

Conclusion We did not find any single factor which would identify accurately which child is likely to have a significant reaction at food challenge requiring IM adrenaline. This reinforces the idea that food challenges can be high risk procedures and need to be carried out by experienced staff.