Being cross allergic to other things might help predict – in French study, 3 phenotypes emerged from cluster analysis:
- Cluster 1 have high level of rAra h 2 (mean 81), low threshold reactive doses for peanut and high proportion of asthma;
- Cluster 2 (mostly boys), have high threshold, milder symptoms, and the lowest proportion of asthma/AR and cross-allergy to TN and/or legumes;
- Cluster 3 have low Ara h 2, high risk of cross-allergy to TN and/or legumes, and most patients suffer from eczema. [Matthias Cousin, Lille, PAI]
Sleep deprivation (sleep overs!) worsened severity of reactions too, by 48% – exercise 28%, not significant. Repeated challenges also seemed to increase severity. [score for severity using Practall criteria.
UK and Europe look at processes as the way to assess risk of contamination with allergens. But not consistent between countries of the EU, let alone globally.
Quantitative methods would appear to make sense – how much allergen is actually present in a given sample? But of course one sample may differ from another (“particulate contamination”). Also difficult to establish minimum eliciting or threshold dose (consider denaturation of the allergen during processing, derived ingredients eg glucose syrup from wheat, soya lecithin, effect of food matrix, individual factors).
Australia and NZ use lowest observable adverse event level (LOAEL) already – warnings required within 10x concentration of LOAEL (“VITAL” threshold, as in toxicology). Studies from Europe and US have found most advisory warnings used for ingredients below the VITAL threshold.
But then it depends on how much you eat, as well as presence of other co-factors that are known to contribute to risk of anaphylaxis.
[BMJ 2011;343:830][Allergy 2021, Paul Turner]