Recommendations and resources
1) Don’t use antihistamines to treat anaphylaxis – prompt administration of adrenaline is the only treatment for anaphylaxis.
For emergency treatment of a severe allergic reaction (anaphylaxis) it is important to promptly administer adrenaline by intramuscular injection using an adrenaline autoinjector if available, or by using adrenaline ampoules and syringe (the latter is only suitable in a medical setting).
There is a high risk of potential harm (disability or death) from anaphylaxis if it is not treated promptly with adrenaline. There are also cost implications from delayed or inappropriate treatment of anaphylaxis, such as additional ambulance, emergency department and hospital costs, as well as additional anxiety for patients and their families or carers.
Antihistamines are recommended for treatment of mild and moderate allergic reactions, including allergic rhinitis (hay fever), but have no role in treating or preventing respiratory and cardiovascular symptoms of anaphylaxis. In particular, oral sedating antihistamines should never be used in patients with anaphylaxis as side effects (drowsiness or lethargy) may mimic some signs of anaphylaxis. Injectable promethazine should not be used in anaphylaxis as it can worsen hypotension and cause muscle necrosis.
2) Alternative/unorthodox methods should not be used for allergy testing or treatment
Whilst there is currently no cure for allergy, reliable tests and a range of treatments for allergy are available, which are backed up by scientific studies that demonstrate proven safety and efficacy.
In contrast, numerous studies have demonstrated the uselessness of several alternative/unorthodox methods that claim to test or treat allergy. These methods continue to be promoted in the community and some even make false claims that they can cure allergy. There is also currently no stringent regulation of alternative/unorthodox diagnostic techniques and devices, so they can be “listed” in Australia without having to prove that they work.
There is a risk of potential harm if individuals with allergies are incorrectly diagnosed and inappropriately treated using alternative/unorthodox methods, particularly if they have severe allergies. The costs of alternative/unorthodox methods are significant, and are usually paid for by individuals, with rebates from some private health funds. There are cost implications for healthcare services as well as individuals, as these funds are being directed into non-productive areas, and are therefore not available for more useful medical tests and treatments.
Examples of alternative/unorthodox methods that have been demonstrated to lack evidence for testing or treating allergy include food specific IgG and IgG4 tests, homeopathy, cytotoxic testing and kinesiology.
3) Allergen immunotherapy should not yet be used for routine treatment of food allergy – research in this area is ongoing.
Research into allergen immunotherapy for food allergy is ongoing and until further work determining safety and efficacy is determined, it should not be performed outside of well defined medical research studies, as there is a high risk of potential harm in individuals with severe food allergy.
Allergen immunotherapy is currently only recommended for treatment of allergic rhinitis (hay fever) due to pollen or dust mite allergy (and sometimes asthma) in appropriate patients when symptoms are severe, the cause is difficult to avoid (such as grass pollen) and medications don’t help or cause adverse side effects.
4) Food-specific IgE testing should not be performed without a clinical history suggestive of potential IgE-mediated food allergy.
Reliable and proven diagnostic tests for food allergy include skin prick testing, blood tests for food specific IgE antibodies and medically supervised food allergen challenges. Allergy test results should never be used on their own, and must be considered together with the patient’s clinical history. In the absence of a history of clinical symptoms, low levels of allergen-specific IgE are usually of little diagnostic significance.
Allergy testing of individuals where there is no evidence that food allergy plays a role in their clinical symptoms increases the likelihood of irrelevant false positive results. This may lead to potential harm due to inappropriate and unnecessary dietary restrictions, with nutritional implications for the individual (particularly in children) and unnecessary fear and anxiety (particularly for the family or carers).
5) Don’t delay introduction of solid/complementary foods to infants – ASCIA Infant Feeding Advice recommends early introduction of solid foods to infants, from 4-6 months old.
This recommendation is consistent with ASCIA Infant Feeding Advice (first developed in 2008) which recommends (early introduction of solid foods to infants, from 4-6 months old (including foods considered to be highly allergenic such as peanut) preferably whilst breast feeding, with no delayed introductions, unless an allergic reaction occurs.
It is important to seek medical advice if an allergic reaction occurs and also regarding the safe introduction of foods if an infant has a sibling or parent with food allergy.
This recommendation is also consistent with findings from recent studies, including the 2015 LEAP (Learning Early About Peanut Allergy) trial published in the New England Journal of Medicine (NEJM). The LEAP trial concluded that the (early introduction of peanuts significantly decreased the frequency of the development of peanut allergy among children at high risk for this allergy and modulated immune responses to peanuts.
Whilst a recent Cochrane review cautioned against the use of this treatment despite finding benefits, this was on the basis that it had only found one valid study with 28 subjects and therefore randomised controlled trials with larger samples were needed to strengthen the evidence.
The recent LEAP trial occurred after the publication of this review and had 640 subjects.