Allergy Frequently Asked Questions

What is an allergy?

This is a reaction produced by the immune system that can lead to symptoms such as nettle rash, large swellings, difficulty in breathing, throat tightness, runny nose etc. Allergies typically occur rapidly following exposure to the trigger (allergen). Severe reactions can be life threatening and therefore correct management is essential.

Does Professor Powell see children?

Yes, he sees children and adults.

Reactions to food – How common are they?

About 20% of the population will experience food reactions, some of these will be food allergies whilst others are food intolerances. A consultation with Professor Powell will ensure that the advice and treatment are correct. Many individuals resort to very limited diets that are not appropriate for their underlying condition and these can be detrimental to both health and well-being.

What are the symptoms of food allergy?

These include hives/nettle rash (urticaria) anywhere on the body, swellings of lips, face and tongue (angioedema), abdominal pain and vomiting, throat tightness/discomfort, difficulty breathing, and in severe cases collapse (anaphylaxis). The onset of these symptoms is often within minutes of exposure and usually within 1 hour. Although the reactions develop rapidly they usually settle within 24 hours. A distinct form of food allergy called the ‘oral allergy syndrome’ consists of intense itching in the mouth whilst eating certain uncooked fruits such as apples, peaches, plums and cherries. This usually occurs in individuals that have allergic rhinitis in the spring caused by tree pollen allergy.

What are the symptoms of food intolerance?

Typically these can include abdominal pain, bloating and distension, nausea, diarrhoea and can be associated with symptoms of tiredness and lethargy. There are specific intolerances associated with for example, Chinese food, milk, wheat, chocolate, cheeses and some red wines. These require full investigation to exclude an allergic cause and to reveal triggers for the symptoms that can lead to helpful dietary/lifestyle changes.

What about allergies to inhaled allergens?

Allergic rhinitis (hay fever) affects 1:3 of the population and can last more than 30 years. Some individuals can be severely affected such that their lives become a misery. Strictly speaking the term ‘hay fever’ should be reserved for grass pollen induced allergic rhinitis, however it is often applied to tree pollen related allergy. The causes of allergic rhinitis include pollens, house dust mite, fungal spores and animals such as cats, dogs, rabbits and horse. Symptoms include sneezing, nasal blocking, runny itchy nose, itchy red swollen eyes and even itching of the ears and throat. Some sufferers also develop wheezing (asthma) on allergen exposure.

When do the symptoms occur?

Seasonal symptoms in the spring are usually related to tree pollens whereas grass pollen causes problems in June and July. Symptoms all year round suggest house dust mite allergy but can be caused by cat and dog allergens.

How is the diagnosis confirmed?

The history is central in the search for an allergic cause but confirmation with allergy skin prick testing is important as allergen specific desensitisation is now available to some allergens.

How should it be treated?

Mild symptoms usually respond to antihistamines and inhaled nasal steroid sprays. Those in whom the symptoms remain troublesome despite this combination will particularly benefit from seeing Professor Powell. Specialist advice on the choice of antihistamine, eye drops and the possibility of desensitisation will be discussed. Nasal sprays are often used incorrectly and to maximise their benefit the correct technique will be demonstrated during the consultation.

Are there other causes of allergic reactions?


Latex allergy can lead to an itchy urticarial rash at the site of contact for example on the hands after wearing rubber gloves, or swelling of the lips after blowing up a balloon. Banana, avocado and kiwi are members of the so-called latex associated foods and if they are eaten by some latex sensitive individuals, can lead to allergic symptoms and even collapse.

Insect stings (bee, wasp and mosquitoes) can cause either large painful local red swellings or widespread hives and anaphylaxis. Investigation directs the correct treatment that can vary from steroid treatment and antihistamines through to life saving treatment such as self-administered adrenaline pens.

Medications such as antibiotics, painkillers and vaccines can also produce allergic symptoms that can be dramatic. Drug allergy identification with advice on alternatives is important for an individual’s future medical care.

Urticaria isn’t always caused by an allergy, is it?

That is correct. Urticaria (nettle rash or hives) is a common condition that affects approximately 20% of the population at some time in their lives. Itchy red blotches occur on the body and the episodes can be alarming. This rash is typically pink/red and raised and it occurs in various shapes and sizes. It can be associated with angio-oedema which are large swellings involving lips, around the eyes, tongue etc. In some the episode settles in a few days but in others it becomes chronic and persists for months/years unless there is appropriate specialist intervention. Although a true allergy may not be involved, specialist advice is needed for this dramatic condition to exclude external triggers such as foods.