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Recognising common allergies in children

Lindsey McManus
Head of Education Allergy UK

In the last 20 years, the incidence of allergy has almost tripled; and with almost 40% of children in the UK now suffering from some kind of allergic disease it is vitally important that conditions such as asthma, eczema, allergic rhinitis and food allergy are recognised at an early age

Often the allergy element of conditions such as asthma, eczema, allergic rhinitis and food allergy is overlooked in general practice, and while treatment is usually adequate, identifying whether a condition such as asthma may be allergy-related can improve the quality of life for these children.

Understanding the mechanisms of an allergic reaction will help in recognising an allergy when a child comes into the clinic or surgery. The Allergy UK Professional Website (see Resources at the end of this article) is an excellent source of advice on all aspects of allergy for the healthcare professional and can show you step by step how to diagnose an allergy.

Although most nurses would recognise allergy if a child presented with swelling of the lips or tongue, a streaming nose and itchy eyes during the summer or a sudden unexplained rash, other conditions may not be so obvious. Most allergic reactions happen immediately after being exposed to an allergen, but there are also delayed responses to food and airborne allergens such as pollens, moulds, pets or house dust mites that can cause symptoms of eczema or asthma.
Some of the most common allergies seen in children are described below.

Allergic rhinitis
Symptoms of allergic rhinitis include inflammation of the mucous membranes, itchy watery eyes, streaming nose, sneezing and blocked nasal passages. There are two types of allergic rhihitis: seasonal (hayfever) and perennial (where the symptoms occur all year round). Allergens responsible for this are pollens from trees, grasses, weeds and moulds. Additional symptoms, such as sinusitis, can also develop at later stages, leading to pain and sometimes infection.

Over 80% of all cases of childhood asthma can be attributed to allergy. Inflammation causes narrowing of the small airways in the lungs, resulting in tightness of the chest, wheezy breathing and coughing, particularly at night. Allergens that can be responsible are house dust mites, moulds and pets.

Food allergy
Symptoms of food allergy can be mild or severe, the severest form being anaphylaxis. Symptoms usually occur immediately after eating the food, and include tingling and swelling of the lips, mouth and throat. In the UK, one in 50 children is now allergic to peanuts. Rashes and urticaria (hives) can also be symptoms of food allergy, with delayed reactions being a common cause of eczema. If a child is anaphylactic to food, EpiPens (adrenalin auto injectors) should be carried at all times or be readily available when in school.

Allergic conjunctivitis
Also connected to allergic rhinitis, children can sometimes develop sore inflamed eyes alongside the usual hayfever symptoms.

Eczema can develop at any age; however, in infants, it may be allergy related (atopic), particularly if there is a history of other allergies. Skin is extremely hot and itchy with dry scaly skin. Skin can become sore and broken when scratched and can become weepy and bleed often, leading to infection. Triggers for eczema include certain foods such as cow's milk and airborne allergens, including house dust mites and pets. Other things to consider are products used in the home, such as bubble baths, shampoos or soap powders.

Oral allergy syndrome
Also known as pollen food syndrome, this condition is becoming far more common in children, with one in 20 now affected. It is usually found in hayfever sufferers who are already sensitised to certain pollen. Some raw fruits, vegetables, nuts and spices have a genetic make-up of proteins similar to that of the pollen that, when eaten, cause itching, tingling and swelling of the lips and mouth. Symptoms occur very quickly but settle down, usually within an hour. This can be avoided by eating the foods after they have been peeled or cooked as this breaks down the allergen in the fruit.

Latex allergy
Latex allergy can cause skin rashes and breathing difficulties and, in its most serious form, anaphylaxis. There is also a possibility of cross reactions with some foods, so people who are allergic to latex may also react to foods including banana, kiwi and avocado.

Insect stings
Insect stings can cause painful reactions around the site of the sting, but some children can also have serious reactions that may indeed lead to anaphylaxis. Avoidance, where possible, is the best route, including not wearing strong perfumes and being aware when eating sweet foods or drinks outside.

Allergy testing
If a child is anaphylactic, EpiPens (adrenalin auto injectors) should be carried at all times. One of the most important tools in recognising whether a child's condition is allergy-related is the taking of a thorough clinical history; often this alone can identify an underlying allergy. Thorough questioning can help identify what allergens the child may be reacting to. For example, if a child presents with what appears to be a year-round cold, questions to ask would include:

  • Do any other members of the family have allergies?
  • When are the symptoms worse (ie, during the day or at night)?
  • Is there any itching of the eyes or mouth?
  • Is the child worse around animals?
  • Are they better on holiday or in different countries?

These kinds of questions may indicate that the child is suffering from perennial rhinitis and is reacting to airborne allergens such as house dust mites (when symptoms are usually worse at night), pets or even moulds. If it is felt that the child is suffering from an allergy it can then be followed up with an allergy test.

The most common forms of allergy test used are skin prick testing or specific IgE blood testing, which should be performed after the clinical history to confirm the diagnosis.
Skin prick testing is simple to do, relatively inexpensive and the results can be seen within about 20 minutes. This is particularly helpful to the patient or their parent as it very clearly shows what they are allergic to. Both skin prick tests and blood tests can have an element of false positive and false negatives, and may only indicate that the patient has been sensitised to an allergen, so allergy should only be diagnosed if there are clear clinical symptoms to that particular allergen.

The term “atopy” is used to define the familial tendency to become sensitised and produce IgE antibodies in response to ordinary exposures to allergens. This terminology should not be used unless sensitisation has been confirmed by skin prick test or blood test.

Allergic march
Children who develop allergies early in life often go through what is known as the “allergic march”. This means that they are prone to develop more allergies during their childhood. Allergies usually develop in a particular sequence, starting with eczema within the first few months of life, following with food allergy, rhinitis and then asthma.

It is worth noting that, often, children will have more than one allergic condition (eczema, asthma or rhinitis) and this alone would lead you to consider that they be atopic. Diagnosis of allergy, along with correct medication, management and support, can make a huge difference to a child's life, preventing the isolation that so often goes along with allergic conditions.

Allergy UK