Allergic Biodiversity succinctly put, is a negative overreaction of the immune system to an allergen (a harmless substance that causes an allergic reaction) and which does not necessarily affect the non-allergic person. Allergic reactions may trigger symptoms in the skin, symptoms of asthma, and even generate a life-threatening reaction called anaphylaxis. In an entire population, only a small fraction can be prone to an allergic reaction. Food allergy now affects about 7% of children in the UK.
Non-allergic biodiversity commonly referred to as pseudoallergic or intolerancesdo not directly involve the immune system. Intestinal gas buildup from beans and cabbage is a good example of food intolerance reaction.
Exposure to a particular allergen may not instantly produce reactions on the first contact; allergy develops after repeated exposure. Sensitisation is a process that takes up to 6 weeks to develop no adverse allergic reaction upon initial exposure to allergens. Sometime later, on repeated allergen exposure, the full-blown allergic reaction will occur. The genetic (inherited) tendency for people to develop allergic diseases is called Atopy.Babies may be sensitised through the skin by their carriers handling them after touching certain foods like peanut.
Sensitisation comes with the production of specific Immunoglobulin E (IgE) antibodies by our white blood cells. On re-exposure,the allergens are bound and attached to Mast Cells (Basophils)by these IgE antibodies, which responds by releasing Histamine and other immune molecules—the beginning of the Allergic Reaction.This manifests with anything from a mild itch to anaphylaxis and death. Inflammation and tissue swelling may follow late phase (Non-IgE) reactions, 6 to 24 hours later.
‘Latent Allergy’ occurs in sensitised persons with positive allergy tests but no allergic reactions. It has no adverse effect as these persons go about, unaware that they’re sensitised.
Common Allergic Manifestations include but not limited to Asthma; Allergic Rhinitis; Atopic Eczema; Contact Dermatitis; Food Allergy; Venom Allergy and Medication Allergy.
A keen interest in allergy and plenty of available time is key for a practitioner (doctor or nurse). In Allergology, 90% of correct diagnosis is achieved through careful questioning by the doctor and the patient’s description of their allergy, followed by a brief examination of relevant organs such as eyes, nose, glands, lungs and skin. Test for allergy shouldn’t be a blind search for an allergic symptom but rather as a confirmation detected from history.
The patient should have a comprehensible educational material on their allergy; this makes for successful future control. A follow-up consultation is necessary for discussion and treatment.
First is 13 years old Victoria with a history of an acute diverse reaction of itching, swelling and collapse after eating a nutty chocolate
Before now, she had eaten chocolate without any problems but attested to avoiding nuts as they made her feel ‘ill’. She had vomited peanut butter as a child and had tree nuts and peanuts removed from her diet by her mum. On this very day, she ate a chocolate bar in the cinema and suddenly noticed that her mouth began to itch, her tongue and face became swollen, her throat began to constrict,and she had an irritating cough. A ‘nettle’ rash began to develop on her face and spread to her whole body, accompanied by a feeling of ‘dread’ before she passed out. She was quickly rushed to the A/E department of the local hospital where she was injected with adrenaline, thenhydrocortisoneand antihistamines were administered and she luckilysurvived.
This demonstrates the importance of identifying the causative agent in the case of anaphylaxis – we tend to use RAST tests or skin prick tests for diagnosing nuts allergy (one can be allergic to one individual nut only or many nuts). We did a mix food screen which was positive and on individual UniCAP tests, she had strong IgE reactions to Peanut and Cashew nut. She was immediately referredfor dietetic advice on nut avoidance, and food label reading. We issued a Medic Alert bracelet and also Epipen auto-injector with a spare at home and school together with Piriton and Prednisilone tablets on hand.
Victoria has had no further reactions and now lives a full and happy life, knowing what to avoid. However, she is unlikely to outgrow the nut allergy.
Marion, 27 years has a 2-year history of fatigue, bloating, weight gain, dizziness and headaches.
She comes from a non-allergic family without any history of eczema, hayfever or asthma. An alternative practitioner‘Nutritionist’ have been visited,andshe had a VEGA Test. From the result of the test, she found out she was allergic to Yeast, sugar, wheat gluten and put on a strict avoidance diet. It was hard for her to adhere; her symptoms saw no improvement.
Seeking the advice of her Practice Nurse on if she was allergic to these foods, we did a food skin test screen and a specific skin test, which includes Yeast and they were negative which wasconfirmed with a blood test.Her Total IgE level was in the normal range. Since protein,not sugar is a common allergen, we checked Marion’s thyroid function,and it was okay. She made a full recovery with regular thyroxine supplementation.
This shows the need to consider alternative diagnosis to allergy even when the patient is convinced that they’re allergic.
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