Frequently Asked Questions

What happens in a consultation?

During the consultation a complete history of the problem will be taken. You also will be able to ask questions and raise any concerns you may have, so that these can be explored with the specialist doctor. A physical examination may also be performed. Depending on the nature of the symptoms, this may be followed by skin prick testing or in some cases, a blood test. A type of lung function (blowing) test may also be performed, known as spirometry or exhaled nitric oxide measurement, particularly if asthma is suspected. These tests maybe performed by either the doctor or one of our practice nursing staff. Following the consultation, your doctor will write a letter summarising the problems, the examination and testing findings together with recommendations for further action. If a blood test has been done, the results will be included with the letter and usually an interpretation will be provided with the letter. You will be sent a copy of this and with your permission, a further copy will be sent to your referring doctor (usually your GP).

Can you test and diagnose in the same consultation?

In many cases it is possible to make a diagnosis in a single consultation. If skin prick testing is performed, these results will be immediately available to you and your doctor for review. Antihistamines interfere with the results of skin prick testing and therefore should be stopped for a minimum of four days before the consultation. If you have concerns about stopping antihistamines or if you are unable to, please contact Allergy London before your appointment. If a blood test has been performed, the results may be needed before a diagnosis is finalised.

In many cases a follow up appointment is not necessary, although this may be recommended if further testing is required. A follow up appointment may also be recommended when the diagnosis and treatment plan is dependent on the outcome of blood test results or other tests scheduled after the initial appointment.

How long will an appointment take?

As your visit may include not only a consultation, but also diagnostic testing, it may take up to 90 minutes. However, this avoids the need to attend on different occasions to have the tests done and the diagnosis discussed. If you would prefer to have the testing done on a separate visit, please let us know at the start of the consultation.

Is there anything I should bring to an appointment?

If you have had previous specialist appointments or testing done, it is helpful to bring copies of these with, or better still, email them to us in advance (info@allergylondon.co.uk). If you are on any medication, please either bring these with or a list of the name, dose and how often they are taken.

If you have had reactions to fresh fruit or vegetables or to an unusual allergen (you can check with our appointments team in advance) then it would be ideal to bring a fresh sample of it with, ideally in the form it would normally be eaten (eg cooked or raw).

What are skin prick tests?

These are the most common test we do in our clinic. They help to tell us whether you or your child is at risk of an immediate allergy to the substance being tested.

It is important that antihistamines are stopped for at least four days before the consultation as antihistamines may interfere with the results of the skin tests.

Skin tests are performed by our doctors or nurse specialists. Drops of allergen extract are placed on the patient’s forearm and then a small lancet (similar to a pin) is pricked onto the skin. The test is not painful but may cause some itchiness. If the test is positive, then an itchy spot or wheal will appear within 20 minutes. The size of the wheal is measured and recorded and then passed to the doctor for interpretation.

Skin tests need expert interpretation to be useful. The diagnosis of an allergy needs both a careful consideration of the patient’s symptoms as well as the test results.

The skin test panels cover all the common food and environmental allergens. If you believe you or your child may be allergic to an unusual food or to a fruit or vegetable, then it is very helpful if you could bring these with you as we can use it to do an allergy test.

Click here for our section on skin prick tests for further information.

What is lung function testing?

These tests can help assess if a patient has asthma and if they do, how well controlled it is. It simply involves blowing into a special tube, attached to a computer. Unfortunately, children under five years of age tend not to be able to master the technique to use this equipment.

Click here for our section on lung function tests for further information.

What is Specific IgE allergen (blood) testing?

Sometimes, it is not possible to do skin tests on a child, for example if they have had antihistamines in the days before the test or the tests may not be conclusive and more information is required. In these cases, a blood test can provide similar information. If you wish, we can put on an anaesthetic cream– this will temporarily numb the skin and help to reduce the discomfort of the blood test. Results take 4-5 days to come back. Please note that these blood tests can be expensive and are performed by an independent laboratory so it is important that you ensure you are able to pay for these if you are not adequately insured.

Do I need a GP referral?

Most insurers will only authorise an appointment if you have a referral from either a GP or another consultant. If you do not have a referral and are a self-funding patient, Professors Fox and Till recommend contacting Allergy London to provide a brief outline of the problem to ensure that a specialist allergy appointment is the best course of action.