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Author:  Australian Allergy CentreSeptember 24, 2015

Food Allergy

A food allergy is an overreaction of the body’s immune system to an ordinarily harmless component within a food. The food is perceived as “foreign” and therefore threatening, so the immune system produces allergen-specific immunoglobulin E (IgE) antibodies to protect the body. In response to an “infestation” the IgE antibodies bind to food allergens; triggering the release of histamine from mast cells and an immediate hypersensitivity reaction.

In Australia, food allergy is estimated to currently affect approximately 10% of infants under one year of age, 4-8% of children under five years of age and 2% of adults. Food allergies are not only common, but becoming more prevalent, more severe and more chronic. A recent study by Mullins et al. (2015) has revealed hospital admissions in Australia for food-related anaphylaxis are increasing at a rapid pace, particularly among older children.

Peanuts, tree nuts, eggs, cow’s milk, wheat, sesame, fish, shellfish and soy are responsible for around 90% of all food allergic reactions. In children, the majority of food allergies are not considered as severe (likely to cause anaphylaxis), and may be “outgrown” in time. For example, approximately 2% of infants are identified to be allergic to cow’s milk and dairy products. However cow’s milk allergy is only observed in a minority of children at four years of age, and is very rare among adults. Allergies to peanuts, tree nuts, seeds and seafood are least often outgrown (ASCIA, 2015).

Symptoms of a mild to moderate food allergic reaction include:
– Itching, burning or swelling of the lips, face and/or eyes
– Eczema or hives
– Abdominal cramps, vomiting and diarrhoea
– Rhinorrhoea, sneezing and nasal congestion
– Watery, itchy eyes

Signs of a severe allergic reaction (anaphylactic shock) to food are:
– Swelling of the tongue and throat
– Breathing difficulties
– Wheezing, persistent coughing and asthma
– Dizziness or loss of consciousness

Anaphylaxis is a potentially life-threatening medical emergency, which requires immediate medical attention for the administration of intramuscular adrenaline (epinephrine). Adrenaline is a first line treatment which rapidly reverses the effects of anaphylaxis, by reducing throat swelling, opening the airways and raising/maintaining blood pressure. For individuals with known food allergies or a history of anaphylaxis, pre-loaded adrenaline auto-injectors (EpiPen® or EpiPen Jr®) are recommended, to keep on hand for emergency treatment of severe allergic reactions.

To diagnose a food allergy is complicated, and individuals should always seek the assistance of a qualified medical professional. If a food allergy is suspected, upon taking a detailed medical history, a skin prick test or allergen-specific IgE blood test may be ordered (ASCIA 2014).

At the Australian Allergy Centre, we have a team of passionate and dedicated healthcare professionals who specialise in the diagnosis and management of food allergies. All medical consultations at the Australian Allergy Centre are bulk-billed and no referral is necessary. Skin prick testing for food allergens is available for $150. This panel covers milk, egg, a variety of grains, seafood, meats, fruits, vegetables and peanut. An extended nut panel is also available for $75. This panel includes peanut, walnut, hazelnut, pecan, pistachio, almond, macadamia, brazil, pine and cashew nuts.

NB: The self-diagnosis of food allergies is dangerous. Self-diagnosis can lead to unnecessary dietary restrictions and subsequent, nutrient deficiencies. Without seeking professional advice, individuals also place themselves at risk for harm associated with the missed diagnosis of other potentially life-threatening medication conditions.

For more information or to book an appointment, contact the Australian Allergy Centre today on 1300 MY ALLERGY.

 

Reference List:

Australasian Society of Clinical Immunology and Allergy [ASCIA]. 2015. Food allergy. Information for patients, consumers and carers. Accessed July 31, http://www.allergy.org.au/images/pcc/ASCIA_PCC_Food_Allergy_2015.pdf

Mullins, R., Dear, K. and Tang, M. 2015. Time trends in Australian hospital anaphylaxis admissions in 1998-1999 to 2011-2012. Journal of Allergy and Clinical Immunology. Published online: July 13, 2015. DOI: http://dx.doi.org/10.1016/j.jaci.2015.05.009