The London Allergy Clinic
Diagnosis & Specialist Care of Allergy & Clinical Immunology
Tel: 07467 133 347
Diagnostic tests we perform
Diagnostic tests done without the interpretation of a Consultant Allergist, having reviewed a patient's clinical history, can lead to wrong diagnosis.
Skin Prick & Intradermal
Skin prick tests can be performed for inhalant allergens, foods and drugs. Intradermal is only performed for drugs. By introducing tiny amounts of the suspected allergens into or just under the skin, our Consultants can observe any reactions within just a few minutes. These reactions are caused by local histamine release at the site of the prick. If you are taking any anti-histamine medication, these should be stopped 3 days before attending for skin prick testing, as they can affect the results.
For certain food allergies, you may be asked to bring along a sample of the item you think has been causing the reaction. The Consultants at the LAC can then prepare this sample for a skin test.
Skin Patch Testing
We use patch testing to investigate Contact Dermatitis. Unlike skin prick testing, patch tests need to be worn for at least 48 hours before our Consultants can evaluate the results.
There are many substances which are frequently in contact with the skin such as natural rubber latex, preservatives, metals, perfumes, cosmetics, leather, chemicals, lanolin and plants.
Additional substances are sometimes added to this list if it is thought they may trigger your skin condition. You can also be tested with some of your own work or home products, such as personal toiletries.
Lung Function Testing
The investigation of wheezing, respiratory infections and asthma may form part of the investigations carried out by our Consultants at the LAC. This is because the nose and lungs are connected by the same airway and are frequently affected by the same allergens.
Not surprisingly, many asthma suffers also have allergic rhinitis. Lung function evaluation complements allergy testing.
Allergens are made up of numerous proteins, with varying levels of stability to heat and digestion. Molecular or component IgE blood tests help our Consultants predict and follow the development of your allergy, uncover any cross-reactions and estimate the risk of a severe reaction.
Such tests can also help identify if any foods that were previously thought off-limits, can be re-introduced by simply taking a more rigorous approach to their preparation, e.g. baking eggs (in cake and biscuits) rather than just boiling or frying them.
The ultimate or “gold standard” test for allergy is exposure to the trigger itself, in a closely monitored environment. This is most commonly done when a food or medication is suspected. Such an allergen provocation test must be done by trained experts under safe conditions. Sometimes this test is required to establish if an allergy has been outgrown or when the history and allergy tests are not in agreement. After an extensive evaluation, our Consultants will be able to discuss whether you might benefit from a food or drug provocation challenge.
Specific IgE Blood Tests
Specific IgE blood tests can provide more detail about your sensitisations and therefore help identify and confirm the causative allergen. In specific circumstances, if a patient wants to obtain an overview of their sensitisations to inhalants and a small range of common foods, a comprehensive IgE screening can also be offered (ISAC). Our Consultants at the LAC will be able to explain the value and the usefulness of all the latest Immuno-diagnostics systems which provide both accurate and consistent results.