Parameters Needed to Estimate the Global Burden of Peanut Allergy: Systematic Literature Review

Abstract

Background: The Foodborne Disease Burden Epidemiology Reference Group (FERG) established by the World Health Organization (WHO) is dedicated at estimating the global burden of a selection of foodborne diseases. Peanut allergy has been included in this initiative because of the severe and potentially fatal symptoms that can be induced. Peanuts are highly nutritious and consumed all over the world. In a small proportion of the population, consumption of peanuts can lead to peanut allergy, which is an overreaction of the immune system caused by otherwise harmless peanut proteins. Peanut allergy develops at an early age, in the majority of patients between 14 and 24 months and it is in almost all cases a life-long problem. Peanut allergy has a large impact on the quality of life of the allergic individuals and their families, since peanuts together with tree nuts, are the most common causes of fatal or near fatal food allergic reactions in children and adolescents. Aims: To define parameters which are essential to estimate the burden of peanut allergy and to make an inventory of the available data for these parameters. Approach: Systematic literature search focused on prevalence and incidence data, duration and severity of the disease, numbers of cases that recover, case fatalities and impact on quality of life. Prevalence data of studies assessing self-reported peanut allergy (questionnaires or interviews), peanut sensitization (positive skin prick tests or peanut-specific IgE antibodies) or clinically confirmed peanut allergy (oral peanut challenges) were all included in this report. Results: Prevalence data were predominantly available from developed countries (UK, Western Europe, Scandinavia, USA, Canada and Australia). There were no data from Africa and New-Zealand and limited data from East and South Europe, Asia, and South America. In Western countries the prevalence of peanut allergy ranges from 0.5%-1.5%. In some countries the prevalence was low or even zero, as has been shown for Israel and Turkey, respectively. This suggests that geographical differences do exist, but it is unclear which genetic, environmental or dietary factors can explain these differences. The symptoms that are elicited when patients accidentally eat peanuts can vary from mild to severe and occur very rapidly after exposure and have a short duration. Due to this short duration, severity of disease is considered to be irrelevant in the burden calculation. Several studies have shown that living with a peanut allergy has a considerably impact on quality of life. One study showed that quality of life was significantly poorer in peanut allergic children compared to children with diabetes mellitus. Compared to allergic asthma, the quality of life score was higher. Quality of life is an important parameter to consider when estimating the burden of peanut allergy. There are limited data on the mortality rate of peanut-induced anaphylaxis and studies report a case-fatality rate between 0.00125 to 0.017 deaths per 100,000 subjects per year. Hence, peanut allergy can be fatal but this occurs rarely. Conclusions: This systematic review has found relevant data that can be used to calculate the burden of disease of peanut allergens in developed countries. The most important parameters were found to be the prevalence and the impact of peanut allergy on quality of life. The mortality rate for peanut allergens is low and probably has a limited impact on the disease burden. Co-morbidities, such as other allergies, might have an impact as well. In the future it should be explored how quality of life and co-morbidities can be included in the calculation of the burden of peanut allergy. The complete RIVM report can be downloaded for free from http://www.rivm.nl/en/Library/Scientific/Reports/2012/april/Parameters_needed_to_estimate_the_global_burden_of_peanut_allergy_Systematic_literature_review. Full report is also available as ‘Supplementary File’.