Single dose oral challenges to validate eliciting doses in children with
cow's milk allergy
Abstract
Background: There is increasing interest in the use of eliciting doses
(EDs) to inform allergen risk management. EDs can be estimated from the
distribution of threshold doses for allergic subjects undergoing food
challenges within a specified population. Estimated ED05 values for
cow’s milk (the dose expected to cause objective allergic symptoms in
5% of the milk-allergic population) range from 0.5mg to 13.9mg cow’s
milk protein. We undertook a single-dose challenge study to validate a
predicted ED05 for cow’s milk of 0.5mg protein. Methods: Participants
were recruited from 4 clinical centres. Predetermined criteria were used
to identify patients reacting to 0.5mg cow’s milk protein (approximately
0.015ml of fresh cow’s milk). Children over 1 year underwent formal
challenge to cow’s milk to confirm clinical reactivity. Results: 172
children (median age 6 (IQR 0.7-11) years, 57% male) were included in
this analysis. Twelve (7.0%, 95% CI 3.7-11.9%) children experienced
objective symptoms that met the predetermined criteria. One participant
had mild anaphylaxis which responded to a single dose of adrenaline, the
remainder experienced only mild symptoms with no treatment required. We
did not identify any baseline predictors of sensitisation which were
associated with objective reactivity to the single-dose challenge using
0.5mg cow’s milk protein. Conclusions: These data support an estimated
ED05 for cow’s milk of 0.5mg protein. Values for ED05 above 0.5mg for
cow’s milk protein proposed for allergen risk management need to be
reviewed.