Vincent St Aubyn Crump
Allergies, including food allergies have increased over the last 20 years. This is partly due to increased public awareness, and a genuine increase, the cause of which we are not entirely certain. The public awareness has been heightened by several reports on food Anaphylaxis in public places & a recent (in the last 2 years) death on an aircraft due to food Anaphylaxis.
The most recent media release last week: "Passengers settle claim with Alitalia and KLM in Peanut Allergy case", confirms the point. This is a story about an Australian woman, a sufferer of Peanut Anaphylaxis, and her travelling companion had booked to fly to Ireland in November 1998 and were cancelled days before they were due to fly out on the basis of the woman’s medical condition.
The shock came for the woman who was an established international traveller with no previous problems based on her condition. Neither Alitalia nor KLM had a formal policy in place at the time of the incident to deal with passengers who suffer from peanut allergies on their flights.
It is obvious that the only way to deal with Life-threatening food Allergies is to increase the awareness to the general public, especially people working in the service Industry. Since there is no cure, or even a drug that can prevent this feared reaction, the only way to deal with it is Prevention & Preparedness.
Food Allergy is estimated to affect between 2 to 2.5% of the general population. A recent survey of the prevalence of peanut & tree nut allergy in the US estimates that 1.14% or close to 3 million Americans is affected.
Despite food Allergy being a fairly common illness, food allergies are among the most frequently misunderstood & misdiagnosed illness especially among children.
Part of this confusion stems from the term "food allergy" is often used very loosely, to mean anything from "I don’t like the taste of this food’ to Anaphylaxis & potential Death.
- Adverse Reaction to Foods: A clinically abnormal response believed due to an ingested food or food additive.
- Food Intolerance: A physiologic response to an ingested food or food additive, which is not proven to be immunologic in nature. This category includes idiosyncratic, pharmacologic (caffeine), metabolic (lactose intolerance) or toxic (scromboid fish poisoning).
- Food Hypersensitivity (Allergy): An immunologic hypersensitivity or truly "allergic" reaction resulting from the ingestion of food or food additive. This reaction involves IgE antibodies & is diagnosed with a Skin Prick Test or RAST test.
- Food Aversion: A psychologically based food intolerance, where a conditioned response is elicited by the recognition, appearance, smell or taste of a particular food. Panic attack is an example of food aversion presenting as Anaphylaxis
- About 2% of adults & 6% of children get food allergies
- About 33% of all Anaphylaxis attending ER is due to foods
- In US 100 — 150 people die each year from foods, compared to 50 dying from bee & wasp sings.
Manifestations of IgE mediated (true) food Allergy
- Atopic Dermatitis
- Urticaria / Angioedema
- Oral Allergy Syndrome
- Rhino conjunctivitis
- Systemic Anaphylaxis
Life-Threatening Food Allergies
Anaphylaxis: rapid, generalized, often unanticipated, immunologically mediated reaction that occurs after exposure to a food in a previously sensitised person.
Reaction can affect virtually any organ in the body.
Common Foods implicated in Life-Threatening Food Allergy:
Foods most often implicated:
Other foods less often implicated:
Food additives & spices may be implicated
- Mustard, sulfites
Prevalence of Life-Threatening Food Allergy
- 1-2% of the general population
- US estimates 1000 cases & 100-150 deaths per year
How is Anaphylaxis diagnosed?
To classify as anaphylaxis we require:
- One symptom of generalized mediator release (flushing, itching, urticaria)
And at least one of the following:
- Oral & Gastro-Intestinal: swelling of tongue, vomiting, diarrhoea
- Respiratory: Rhinitis, wheeze, stridor
- Cardiovascular: low blood pressure, irregular or rapid pulse, faint or shock
The only exception is isolated laryngeal oedema or shock / syncope after injection.
Fatal Food Anaphylaxis: Risk Factors
- Peanut or Nut sensitivity
- Previous episode of anaphylaxis with incriminated food(s)
- Food eaten away from home
- Accidental ingestion
- Denial of symptoms, delay Treatment
- Lack of use of Adrenaline
- History of Asthma plus food Allergy
Emergency Treatment of Anaphylaxis
- Adrenaline is the only life saving drug in the treatment of Anaphylaxis
- 0.3-0.5 mg 1:1000, i.m.
- Adrenaline is rapidly Metabolised, may need to be given every 12-14 minutes
- I.V. Fluids: colloids or crystalloids
- Other: (Secondary) Antihistamine, Steroids
Beware of Relapse (Bi-phasic response), Therefore observe for 4-6 hours
When should Adrenaline be given?
"3 D Rule of giving Adrenaline"
- Definite reaction to nuts
- Death a possibility
Only 2 things threaten life. The "2 D Rule"
- Difficulty Breathing (either due to swelling or asthma)
- Deteriorating Consciousness
The 1 "1 D Rule"
- Do give Adrenaline if in Doubt
In mid 1998 the Department of Transport (DOT) issued a proposal mandating that the 10 major US Airlines must provide "peanut-free zones" for passengers with peanut allergy…This met with great resistance with the Air Transport Association…the US congress…. the mandate was never implemented.
Why banning Peanuts won’t work
- No such thing as a peanut-free flight. Will they do a body search?
- "Peanut-free" gives everyone a feeling of false security, which in turn encourages complacency
- When a ban goes in place the emphasis moves from education & raising awareness to enforcing the ban
- There are lots of other life-threatening food triggers such as sesame, milk, eggs, fish & wheat. Where do we stop?
Education of patients (so that they can take responsibility for themselves) and the general public so they can assist in avoiding deaths due to accidents is a more useful proposal.
Peanut Allergic Reactions on Commercial Airlines
A recent study done in Feb ’99 (& Published in the American Journal of Asthma, Allergy and Clinical Immunology) addressed the subject as to wether aerosolised peanut does cause allergic reactions in planes.
The study involved 3,704 people from the Peanut & Tree nut Allergy Registry. They answered a questionnaire & had follow-up consultations.
Severe reactions to peanut on flights are primarily due to ingestion, but respiratory reactions occurred from inhalation when passengers are consuming peanuts. These inhalation reactions were not life threatening. They would occur on the same mechanism as a cat allergic person who gets rhinitis, watery eyes & wheezing on entering a room where there is a cat.
What can Airlines do to reduce anxiety & deaths amongst food allergic patients?
- Educate all staff on Food Anaphylaxis to alleviate passenger anxiety
- Flight Attendants should be knowledgeable on Anaphylaxis and how to treat it.
- All airlines should carry Adrenaline, which can be easily used by the staff on board eg Epi-Pen. Several of these should be on board Obtain indemnity if necessary
Since all fatalities from foods are accidents, the staff on board should be equipped to deal with emergencies arising from foods served on board & foods taken on by passengers.