Hills Allergy and Specialists Clinic
Food and Other Allergies
Allergy occurs when a person reacts to substances present in food or environment that are harmless to most people. These substances are known as allergens and are found in food, dust mites, pets, pollen, insects, ticks, moulds, and some medications.
Atopy is the genetic tendency of a person to develop allergic diseases. When atopic people are exposed to allergens, they can develop an allergic/immune reaction. Depending on what a person is allergic to, the following symptoms can develop:
- Food allergic reactions; mild to moderate or severe allergic reaction (anaphylaxis)
- Nose and/or eyes, resulting in allergic rhinitis (hay fever) and/or conjunctivitis
- Skin resulting in eczema, or hives (urticaria)
- Lungs resulting in asthma
SYMPTOMS of an allergic reaction to food?
Food allergy (IgE mediated allergy) occurs in around 10% of infants, 4-8% of children, and about 2% of adults in Australia. The most common food allergens are egg, cow's milk (dairy), wheat, peanut, tree nuts, sesame, soy, fish, and shellfish. Almost any substance that is eaten (including herbal medicine) can trigger an allergic reaction.
If you are allergic to a food, symptoms usually start within minutes to an hour of exposure to the food you are allergic to. The symptoms can be mild to moderate or severe. Severe allergic reaction (anaphylaxis) can be life threatening and needs immediate treatment.
Signs and symptoms of mild to moderate allergic reaction include:
- Red rash / hives around the mouth, face or body
- Itchy lips, mouth, tongue or throat
- Swelling of eyes, lips or face
- Stomach cramps/pain, nausea or vomiting (Abdominal pain, vomiting - these are signs of anaphylaxis for insect allergy)
- Diarrhoea
Signs and symptoms of severe allergic reaction (anaphylaxis):
- Difficulty or noisy breathing
- Tongue swelling
- Swelling, tightness or feeling of lump in the throat
- Difficulty talking or hoarse voice
- Wheeze or persistent cough
- Persistent dizziness or collapse
- Pale and floppy (young children)
Mild or moderate food allergic reactions are common in Australia. Severe allergic reactions (anaphylaxis) due to food allergy are less common and deaths from anaphylaxis are rare.
Most deaths from anaphylaxis can be prevented by:
- Careful food allergen avoidance;
- Correct posture during a reaction (laying flat, in recovery position or sitting with legs outstretched); and
- Prompt administration of adrenaline (epinephrine).
Food protein-induced enterocolitis syndrome (FPIES):
FPIES is a delayed (non-IgE mediated) gut allergic reaction to a food or foods. It usually presents with repetitive, profuse vomiting that typically starts one to four hours after a triggering food is eaten. Some babies can become floppy, pale, cold and develop diarrhoea.
The most common triggers for FPIES are cow’s milk, rice, oat, and egg, however, any food can trigger FPIES,
SYMPTOMS of an allergic reaction to environmental allergens?
Allergic rhinitis (commonly known as Hay Fever) affects around 18% of people (children and adults) in Australia. The symptoms are caused by allergy to dust mites, pets, pollen, or moulds.
Symptoms range from mild to severe and can affect day to day function. Symptoms may occur throughout the year, seasonal or exposure to a particular allergen such as animal dander. It is important to note that allergic rhinitis is not caused by a food allergy.
Immediate signs or symptoms
- Runny nose
- Itchy nose
- Sneezing
- Itchy, watery eyes
Obstructive signs or symptoms
- Congested/blocked nose
- Snoring
- Chronic mouth breathing