Peanut allergy: later onset linked to anaphylaxis risk
6 March 2009
Children who develop peanut allergy at an older age may have an increased risk of anaphylaxis (a sudden, severe, life-threatening allergic reaction) compared to those with earlier onset.
A retrospective study (a study that looks backwards in time), the first to provide direct evidence of rising rates of peanut allergy in Australia, was conducted in 18,028 patients attending an ACT community-based allergy practice from 1995 to 2007 (J Allergy Clin Immunol 2009, online).
The researchers found 751 patients with peanut allergy, of whom 90 per cent experienced their first peanut allergy reaction at less than 6 years of age. In this group, the risk of anaphylaxis increased by 22.7 per cent for every additional year of age at onset.
The authors said their findings raised the interesting possibility that delayed introduction of allergenic foods (foods that may cause allergies) might increase the risk of more serious reactions.
Associate Professor Mimi Tang, consultant paediatric allergist and immunologist at Melbourne’s Royal Children’s Hospital and one of the study authors, said the study wasn’t designed to look at when to introduce food but pointed towards a benefit of earlier introduction.
‘Perhaps if you introduce the food a bit earlier, if you were going to be allergic at least it might be a mild reaction, rather than a more severe one,’ she said.
‘What you can say very strongly is that delaying the introduction of these foods doesn’t protect against allergy. It’s not doing you any benefit, and what our study shows is that the earlier you have your reaction, the milder it is,’ she said.
A study published late last year showed that introducing peanut protein early in infancy may actually prevent, rather than promote, the development of peanut allergies in childhood (Medical Observer, 21 November 2008).
Meanwhile, a recent UK study showed for the first time that oral tolerance to small amounts of peanuts could be induced in children with peanut allergy (Allergy 2009, online).
Last Reviewed: 06 March 2009
- 1. Mullins RJ, Dear KB, Tang ML. Characteristics of childhood peanut allergy in the Australian Capital Territory, 1995 to 2007. J Allergy Clin Immunol 2009, online
2. Clark AT, Islam S, King Y, et al. Successful oral tolerance induction in severe peanut allergy. Allergy 2009, online
