An allergy is an adverse reaction of the body’s immune system to a substance which is harmless to most people.
For some, suffering from an allergy is not a "real" disease. Yet more and more people, adult and children, are living with some form of allergy. The World Health Organization ranks allergy as the 4th disease in the world. Food allergies have doubled in the past decade and asthma, rhinitis and eczema have trebled in the past 20 years.
An allergic reaction can lead to a variety of symptoms such as sneezing, wheezing, sickness, itchiness, red eyes, most of which are mild and not life-threatening. However a small number of people can develop severe allergic reactions (anaphylaxis) which can put their life in danger.
Allergies are not always straightforward to diagnose, especially in children. Diagnosing and managing allergies helps restore quality of life and is done by Allergists. At The Medical Chambers Kensington, Dr Sophie Flammarion deals with allergies in babies and children, from screening to sub-lingual immunotherapy. Dr Alina Dumitru sees adolescents and adults for all types of allergies. Both are Consultants at St Thomas’s Hospital, London. Other specialists deal with allergies on a daily basis: Ms Romana Kuchai, ENT Surgeon, has a special interest for allergic rhinitis; Mr Nabeel Malik, Ophthalmologist, treats allergic conjunctivitis; Dr Veronique Bataille, Dermatologist, offers diagnostic tests for contact allergies.
At The Medical Chambers Kensington our Consultants offer skin prick tests, patch tests, allergy blood tests, as well as in some cases sublingual immunotherapy.
Other tests such as allergy challenges must be carried out in a hospital environment under close medical supervision but can be organised by your specialist.
What is an allergen?
An allergy is an excessive immunological reaction that occurs when the body comes into contact with an allergen - usually a harmless protein:
- food (eggs, milk, peanuts, wheat, fish ...),
- insects, mites,
- grass pollen, dust,
- drug substance.
The reaction may be sudden and/or persistent and with no obvious cause. The immune system develops antibodies (IgE) at the first contact with an allergen which will then trigger symptoms (the allergic reaction) at any subsequent contact.
Symptoms can affect all parts of the body in contact with the external environment:
- Eyes, nose, throat and ears: conjunctivitis, sinusitis, cough, laryngitis, rhinitis...
- Skin: eczema, urticarial (itchiness, rashes), oedema...
- Respiratory system: asthma, cough...
- Digestive system: vomiting, diarrhoea, constipation, abdominal pain...
Reactions can be immediate or appear "delayed". Their severity is variable, which explains why an allergy can go unnoticed for a long time but have a significant impact on daily life: fatigue, irritability, breathing difficulties, diarrhoea, weight loss, disturbed sleep, headaches. These symptoms affect not only the well-being but also the working life or the schooling of children (problems concentrating, sleep disorders ...).
Diagnosis and management
Learning to live with it is not enough. Nowadays, Allergists can offer diagnosis and management to determine the origin of the symptoms, whether acute or chronic. Once an allergy is diagnosed and treatment implemented, the effects of the disease will be minimised. Not addressing the cause of the problem can lead to an aggravation of symptoms. It is worth remembering that the existence of one or more food allergies in early childhood is a risk factor for the development of other allergies.
Your specialist will consider in the first instance the history of the disease and its symptoms; he will be able to reassure you, and after the clinical examination suggest several types of tests:
- Skin prick tests
- Blood tests
- Patch test (for contact allergies)
- Challenge test (undertaken in hospital)
A skin prick test or a blood test proves sensitivity which is not necessarily an allergy. Being able to establish the cause of an allergy allows you and your specialist to devise the most appropriate management strategy; for example, identifying which food items you are allergic to will avoid unnecessarily restrictive diets. Similarly identifying dust mites as the main culprit for your child’s asthma will help you put in place the right measures to improve his quality of life.
Beware of diagnostic kits sold online, the reliability of which is at best questionable.
The management of allergy is discussed with your specialist and can include
- Desensitisation (immunotherapy)
- Environmental control
- Therapeutic education
Even with optimal management, it is worth noting that peanut allergy rarely disappears. The same applies to other nuts, fish and crustaceans allergies. However, allergy to cow's milk tends to disappear in more than 80% of cases and egg allergy disappears in more than 50% of cases before the age of 6.