Högskolan i Skövde

Background: Subjective symptoms after food challenges are difficult to interpret and no standard is available. We discuss a strategy for how to interpret a diary. Furthermore, the interobserver reliability is evaluated.

Methods: Diaries for 32 patients with subjective symptoms were used. The diaries were re-evaluated with a predefined strategy by three independent observers.

Results: The proportion of positives was 21.9% among the old diagnoses, according to the new approach 34.4% (observers I and II) and 37.5% (observer III) were positive. The new approach had high interobserver reliability (97 and 100%).

Conclusions: The proportion of positives depends on how subjective symptoms are interpreted. Interpretations of subjective symptoms in diaries could be made with high interobserver reliability.

The double-blind placebo-controlled food challenge (DBPCFC) is the gold standard for diagnosing food hypersensitivity (1–5). However, DBPCFC needs further standardization regarding essential issues, e.g. quantity of food, vehicles, blinding, dose titration and interpretation of symptoms (2, 3, 6–10). This study highlights the latter problem. For patients with several subjective symptoms that may occur in various degrees both on active and placebo provocations, a standardized strategy for interpretation would be valuable. Bindslev-Jensen et al. have theoretically illustrated that there may be great differences dependent on how placebo symptoms are treated (11, 12) and in a position paper (13) it is suggested that in situations when only subjective symptoms are present, several provocations must be used. The lack of an interpretation standard may be one reason for explaining the doubts regarding the value of subjective variables for making a diagnosis (9, 14). We discuss a strategy for how to interpret the symptom profile found in such a mixed sequence of active and placebo provocations. Furthermore, the interobserver reliability is evaluated.