About Your Appointment

Frequently Asked Questions

What caused my allergic reaction?

Sometimes the cause of an allergic reaction is obvious, because a single trigger was given immediately before a reaction. Having said that, it may still be important to rule out every single other possibility, however unlikely, because the consequence of failing to identify the cause correctly can be very serious. In the case of allergy under anaesthesia, so many drugs are being given into your bloodstream so close together, that it can be impossible to know what the trigger was for certain without specialised testing.

Why do I need skin testing?

Skin testing is the technique we use to identify the cause of an allergic reaction. Like any medical test it isn’t perfect, but overall it is extremely sensitive and specific. It is the best test we know of for determining what triggered an allergic reaction

What does skin testing involve?

In simple terms it involves injecting tiny amounts of very dilute substances into the very top layer of the skin and looking for a small rash to form around the injection site when your body is allergic to the substance.

How soon can I be seen after an allergic reaction?

You can be seen as soon as you have recovered from your immediate reaction, but skin testing itself is ideally delayed for 4 to 6 weeks following a suspected anaphylactic reaction. Tests done before this time can be unreliable.

How long does skin testing take?

If you come to QARC for consultation and skin testing, then expect to be there for 90-120 minutes. If you are just attending for a consultation, then expect 30-45 minutes.

Will I need blood tests?

In some cases, our doctors may request that you have blood tests either before or after your appointment. These tests cannot replace skin testing, which is the most accurate method for determining the cause of allergy, but in complex cases they may add certainty to the results or rule out other immune system diseases.

How long do the skin testing results take to be obtained?

Usually the doctor performing your testing can give you preliminary results on the day of the test, and often you will be able to re-book your operation immediately, if your original surgery was cancelled due to anaphylaxis. Results will then come to you by mail within 5 business days. You will get a copy of the same results that all the doctors involved in your care receive.

Is there a chance I may need further skin testing?

In some circumstances you might, although it is uncommon because a clear answer can usually be found. If you test positive to certain drugs, such as antibiotics, then a plan can be made for a safe return to surgery, but it might be recommended for you to undergo further testing to fully determine the extent of your allergy to other related drugs in that drug family.

Why have I been recommended to have a drug challenge?

We use drug challenge when we want to prove negativity of a drug beyond doubt. It offers a guarantee that re-exposure will not lead to allergy.

What does a drug challenge involve?

Drug challenge involves monitoring you while you are given a small dose of drug, where you are believed to not be allergic to the drug. A challenge may involve a single dose, or sequentially higher doses of the drug, depending on what the drug is.

What are the risks of drug challenge?

The vast majority of drug challenges are negative, as expected. If positive, then a person will develop symptoms of allergy. Because this occurs under observation, while being carefully monitored, treatment is usually straightforward. There is a very small risk of a serious reaction which would require adrenaline treatment.

Do I need a Medical Alert bracelet?

The purpose of a Medical Alert bracelet is to notify healthcare providers of your allergy in situations where you may not be able to do so yourself, for example if you are unconscious or critically injured. In most cases, if you have a positive skin test to a drug after having had anaphylaxis, then we will recommend that you obtain a Medical Alert bracelet or equivalent. We will explain to you how to do this and assist if necessary.

Do I need an EpiPen?

The purpose of an EpiPen is to allow you or another person to deliver emergency treatment if you have an anaphylactic reaction away from a health care setting. Some drugs are so specific to the operating theatre that there is no realistic chance of being exposed to them in the wide world and an EpiPen is not necessary. For other substances we may decide that you need to keep an EpiPen. If so, then we will prescribe it for you and train you in its use.

Will any of my regular medications interfere with my skin testing?

Potentially, some medications can make skin testing results unreliable. The most important of these are the antihistamines, which need to be completely ceased if possible, prior to your appointment. We will provide you with information prior to your appointment on which drugs to notify us about. In some cases, certain drugs cannot be ceased for safety reasons, and skin testing can still proceed in these cases, but the results can become more difficult to interpret.

Is skin testing safe?

Skin testing is a common test performed all over the world for all types of allergies and is extremely safe, but some very rare risks exist. Our doctors will discuss all the risks and benefits of testing, including the risks of not testing, during your consultation.

Will any of my medical problems interfere with my skin testing?

There are very few medical reasons that would prevent someone from having skin testing o interfere with the results, but there are some. Our doctors will ask you about all these conditions at your consultation.