Bulletin April 2022 Number 198

Immunologists are doctors and scientists who deal with the study, diagnosis and management of patients with disordered immune systems that are a result of acquired and inherited conditions or some blood cancers. They also advise on conditions in which immunological treatment forms an important part of therapy and/or prevention. Some immunologists specialise in treating allergies. Here, Dr Tomaz Garcez discusses fatal anaphylaxis and the role of the UK Fatal Anaphylaxis Registry.

Any fatality related to allergy is devastating. These events often occur in otherwise healthy individuals. When an event does occur, it is critical to confirm that the fatality was related to allergy and identify the causes and potential contributing factors. Forensic pathologists, allergists and clinical immunologists are critical to the evaluation of these cases and present their findings to the coroner involved to identify any learning.

Fatal anaphylaxis is a rare but devastating occurrence. Analysis of trends in anaphylaxis over the period from 1992 to 2012 showed an increase in anaphylaxis hospital admissions (up by 615%), but fatality rates remained stable at 0.047 cases per 100,000 population.1 There have been several high-profile media cases of fatal anaphylaxis in recent years, often in younger individuals and related to already known food allergies. One of the recent cases has resulted in Natasha’s Law, relating to food safety.2

The UK Fatal Anaphylaxis Registry (UKFAR), held at Manchester University NHS Foundation Trust (MFT), is supported by the British Society for Allergy and Clinical Immunology (BSACI) and patient support groups including Anaphylaxis Campaign and Allergy UK. UKFAR was set up by Dr Richard Pumphrey in 1992 to collect and analyse data on suspected cases of fatal anaphylactic deaths from any cause, facilitating identification of patterns and a better understanding of the risks and causes, and contributing to national and inter-national guidance. This will ultimately provide knowledge to reduce the risk of future deaths from anaphylactic reactions. UKFAR has received a grant from the Food Standards Agency (FSA) to continue its important work.

There has been a build-up of unevaluated cases of fatal anaphylaxis due to the retirement of Dr Pumphrey. Recently, BSACI and FSA have supported UKFAR to evaluate the cases in the backlog. Dr Vibha Sharma, Consultant in Paediatric Allergy at the Royal Manchester Children’s Hospital and current custodian of the registry, explains that ‘...our existing understanding of why some allergic reactions are catastrophic leading to death, when many respond to treatment, is lacking. Fortunately, fatal anaphylactic reactions are rare. Each of these unfortunate events must undergo detailed scrutiny to help improve outcomes and avoid unnecessary deaths in the future.’

Ongoing case collection is essential in understanding how the management of those with anaphylaxis may be improved.

Through the registry various reasons explaining why treatments such as auto-injectors have failed to rescue patients have emerged. Ongoing case collection is essential in under-standing how the management of those with anaphylaxis may be improved.

We know that there has been a year-on-year increase in admissions to intensive care following anaphylaxis. Given the increase in admissions with anaphylaxis, the work of UKFAR remains extremely important. UKFAR encourages the submission of suspected cases and can advise on the collection of accurate and comprehensive data in any fatal cases to ensure high-quality clinical and pathological information is not lost.

Fortunately, fatal anaphylactic reactions are rare. Each of these unfortunate events must undergo detailed scrutiny to help improve outcomes and avoid unnecessary deaths in the future...

UKFAR can also advise on the investigation of cases and asks that you contact us for advice on any suspected fatal anaphylaxis cases, ideally as soon as fatal anaphylaxis is considered. This will facilitate collaboration for important data and evidence gathering. Early involvement of UKFAR in the assessment of suspected fatal anaphylactic events can help identify contributing factors and to guide or focus post-mortem assessment.

UKFAR would also appreciate any information you can provide on past cases that may be in our backlog or that may not yet have been identified by our searches. Please contact us to help update any cases of fatal anaphylaxis you may have been in involved with previously.

References available.

Testimonials

Dr Gemma Petts, a consultant paediatric pathologist, said: ‘As a paediatric pathologist carrying out coronial post mortems to ascertain the cause of sudden unexpected deaths in infants, children and adolescents, the possibility of anaphylaxis as a cause for collapse is not infrequently raised by members of the team involved in the early stages of the Child Death Review process. In some cases, the history and circumstances make anaphylaxis an unlikely factor in the death. However, I have encountered a number of cases where a fatal reaction to food or drugs is strongly suggested by the circumstances. In both scenarios, I have found the UKFAR team easy to approach for advice and guidance. The UKFAR team has always taken time to discuss the cases with me and provide clear advice on appropriate sampling. The team has a good understanding of the post-mortem process, its limitations and the constraints around tissue sampling. In cases where samples have been collected and analysed, the UKFAR team has communicated the results clearly and directly with me. They have always been on hand to help interpret and discuss the results, again on a case-by-case basis. The expertise of the UKFAR team is invaluable in the investigation of these deaths and vital to ensuring we continue to identify and learn from every fatal case so that there is a better understanding of the risks and causes of fatal anaphylaxis.’

Professor Adam Fox, President of the BSACI, has said: ‘Working with MFT on the UK Fatal Anaphylaxis Registry is hugely important and the BSACI are grateful to the FSA for supporting the UKFAR. This will ensure sustainability and aid engagement with the coronial system, which is one of the key agencies UKFAR relies on to provide details of all cases of suspected fatal anaphylaxis. This funding is a one-off grant, however long-term funding is needed to support the registry thereafter. There has been a lot of media coverage of fatal anaphylaxis recently, which has brought to the fore the critical work of UKFAR.’

Sushma Acharya, Head of Policy and Strategy for Food Hypersensitivity at the FSA said: ‘Food hypersensitivity is a priority for the FSA and we are delighted to support the UK Fatal Anaphylaxis Register with this grant. The work of the register will be important in helping us better understand the prevalence of anaphylaxis-related deaths and our understanding of the risks and the causes, which could help reduce the risk of recurrence. This funding will help bring the register up to date and stabilise it, so ensuring that it remains an important resource to use in the future. Our support of this work, which forms part of our Food Hypersensitivity Programme, builds on the existing body of research work we have funded on food hypersensitivity, including current work to use NHS data to monitor trends in severe allergic reactions.’