Rising Trends in Food Allergies: A 20-Year Study from England

Food allergies are becoming more common according to a new study led by Dr Paul Turner from Imperial College London, highlighting the growing number of cases in England over the past 20 years. The study, published in The Lancet Public Health, looked at data from 1998 to 2018 to understand how food allergies are being diagnosed and managed by the healthcare system.

Key Findings:

The study, which looked at data from over 7.6 million patients, revealed several important trends:

1. Sharp Increase in Food Allergy Diagnoses

The number of new food allergy cases almost doubled between 2008 and 2018. Specifically, the rate of probable food allergies rose from 75.8 cases per 100,000 people per year in 2008 to 159.5 in 2018. This increase was especially noticeable in children aged 0-4 years, with 4% of this age group affected by 2018. Across all ages, the overall number of people with food allergies went up from 0.4% to 1.1%.

However, categorising food allergies as possible or probable based on medical codes can be inaccurate. These codes might not always be used consistently in health records, which could lead to either overestimating or underestimating the actual number of allergy cases. Additionally, the difference between IgE-mediated and non-IgE-mediated allergies isn’t always clear, which could make it harder to accurately understand how common these allergies are.

2. Differences Across Age Groups

The study found that food allergies are most common in young children, with 4% of those under five affected. This drops to 2.4% in school-aged children, and further decreases to 0.7% in teenagers and adults. These results suggest that many children may outgrow their food allergies as they get older.

3. Gaps in Prescribing Adrenaline Auto-Injectors (AAIs)

Despite the increase in food allergy diagnoses, the study revealed a concerning gap in the prescription of adrenaline auto-injectors, which are essential for treating severe allergic reactions (anaphylaxis). Only 58.3% of people with a history of anaphylaxis had been prescribed an AAI. This gap was even bigger in more deprived areas, where people were less likely to receive an AAI prescription.

4. Managing Food Allergies in Primary Care

Most food allergy cases (88.4%) were managed only in primary care settings including the majority of young children (primary care refers to the first point of contact within the healthcare system where patients receive care for most of their common health needs, e.g. GP). This is worrying because guidelines recommend that people with severe allergies, especially those who have had anaphylaxis, should be referred to a specialist. The study suggests that a lack of specialist allergy services and knowledge in primary care might lead to missed opportunities for better management, such as reintroducing certain foods or considering new treatments like immunotherapy.

5. Challenges in Accurate Diagnosis

The study also noted that diagnosing food allergies accurately can be challenging. The data relied on how food allergies were recorded in the healthcare system, which could lead to overestimates if conditions were incorrectly coded as “possible” food allergies. On the other hand, some cases might have been missed if healthcare professionals did not recognise allergy symptoms. This shows how tricky it can be to track food allergy trends accurately.

6. Impact of Public Health Advice

Interestingly, the study observed that the number of new food allergy cases started to level off from 2014 onwards. This could be linked to public health advice encouraging parents to introduce common allergenic foods like peanuts and eggs into babies’ diets early on, which has been shown to reduce the risk of developing food allergies. However, more research is needed to confirm this and to understand the long-term effects.

In conclusion, Dr Turner’s study provides important insights into the rise of food allergies in England. While the growing number of cases, particularly in young children, is concerning, the research also highlights significant gaps in how these conditions are managed. Making sure that those at risk of severe reactions get proper care, including access to adrenaline auto-injectors, is crucial. Additionally, it’s important to improve education for healthcare providers, especially in primary care, about the complexities of food allergies. As food allergy rates continue to rise, public health strategies and clinical practices must adapt to better manage and support those affected.

Future research is needed to investigate the quality of life, psychological effects and long-term health outcomes associated with food allergies. Understanding these impacts would inform the development of comprehensive care models that address not only the physical but also the emotional and social aspects of living with food allergies.

Read the full report here:  Time trends in the epidemiology of food allergy in England: an observational analysis of Clinical Practice Research Datalink data – The Lancet Public Health