Allergy Testing

When you suspect an allergy , unless you have a very clear reaction, it can be difficult to navigate potential symptoms. Are you reacting to something else, is it hay fever, are you having a mild reaction, do you have a skin condition or is there something else underlying? It can be mind boggling and even be a long time without a clear answer.

You can attempt allergen eliminations on your own; however in order to get clear results, ensure you get the correct treatment and medical support, it's vital you keep your medical professional in the loop of any reactions you have and suspected allergens, tests you need or have had outside of their care.

Below are some of the tests you may be put forward for, all of which can aid in finding a known allergy or even shed light on an unknown allergy. 

I myself had no idea I had so many allergies (Milk, Peanuts, Nickel, Animal, Pollen, Dust.....it's a rather long list) until I underwent both blood and skin prick tests, but have suffered years with many symptoms, putting them down to just having bad skin, Hay Fever or colds (or general poor health) - knowing the allergens I am allergic to has helped me to managed all symptoms and mostly they have cleared or calmed since.

Skin prick tests are one of the most common and quickest ways of finding an allergy. It involves a patient having multiple allergens placed on their skin and essentially pricked with a small needle, which introduces the substance into the body to see if a reaction occurs. They are very safe way of testing, with less than 0.02% resulting in a severe reaction.

They can be carried out on patients of any age, however there is reluctancy on doing multiple tests on young children as they can be traumatic, and as they are small it limits the amount of allergens that can be tested at one time, often needing repeated testing.

Depending on how many allergens are to be tested will depend on what location of the body the test will use and how long you will need to wait for results. Some people may have a small area tested, such as forearm with several allergens, however some people may require many more allergens to be tested resulting in their entire back needing to be used.

The specialist testing the patient will mark out numbered areas on their skin with either a marker or tape, control areas and substances are also added. Small drops of liquid allergens are then dropped onto the skin in one of the numbered zones and upper layer of your skin is scratched with a needle (which looks more like a paperclip than needle, and a new one used on each allergen to avoid cross contamination) to introduce the allergen to into your body and immune system. 

Once the skin has been scratched, the remaining liquid is dried up with paper towel and a wait of 20-30 minutes ensues test. If a reaction occurs, the person will have symptoms at the site of allergen introduction, not dissimilar to an insect bite. The specialist will use a measure to measure the affected area and note the severity of the reaction and the controls. This allows them to see which allergens a person is allergic to and the how severe they may react to and allergen based on the results.

Result are usually immediate at the test appointment  and antihistamines are given if an allergy occurs.

Like Skin prick tests this is also one of the most common allergy tests. It involves the e=same principle of the skin prick test, just without the skin scratching and a longer wait. Once again the patient has multiple allergens placed on their skin, however they are covered by little metal discs and left on the skin for 24/48 hours before being removed. 

They can be carried out on patients of any age, however with this form of testing is lengthy and as you can imagine children are reluctant to keep dressings on, which can make it harder doing this type of test of children.

Areas on the skin are marked out in a grid like fashion, yet again adding in control areas alongside allergens used. Allergens are then placed onto the skin in one of the grided zones and these are then covered with tiny metal discs almost plate looking. Some tests may introduce allergens direct to skin already loaded in such discs, these are then taped securely to the skin. 

The patient is then to go home and wait 24/48 hours before removing the  If a reaction occurs, the person will have symptoms a test patches and are unable to wash the area for a long period of time, allowing the allergens to absorb in through the skin and provoke a reaction.

If a reaction occurs, similarly to the Skin Prick test, they tend to be local to the allergen origin, looking more like a rash or insect bite. Patients are usually asked to take pictures everyday between appointments (normally a few days to a week) to refer to to and review the outcome of reactions. 

At the next appointment the specialist will use a measure any affected areas and note the severity of the reaction and the controls. They'll be able to tell results at the return appointment and provide treatments/advice.

Blood tests are considered to be the most accurate type of test  for finding allergies. Blood samples are sent off to a lab, where they introduce allergens directly into the blood sample, the blood will then react or not with the allergens producing antibodies to attacks. 

These antibodies or IgE levels are then measured and noted in a scale of 0-5 for each allergen tested, and then are sent back to your medical professional for reading. The results not only show which allergens where tested, but also the level of  IgE antibodies that are produced when exposed to each allergen. 

With these results, you'll be able to find out how allergic you are to an allergen and if you need treatment or other testing.

Food challenges are a type of provocation tests as they provoke a reaction in a patient, which is used to see how heir body reacts to an allergen and how much allergen is needed before a reaction happens.

The patient is given small amounts of a food allergen in intervals, usually 20-30 minutes. At each interval the portion size of the allergen is increased. I.e. you start with a marble size slice of cake, increased to quarter, then half, then three quarters and a whole.   

Over the course of the test the patient is monitored by their specialist and tester for any symptoms, it may be hives, itching, and any other symptoms. if any occur the test stops and antihistamines are administered. the patient is left to recover before being released home. 

This is a good tool for Children who may grow out of an allergy, as specialists can monitor if there is an increase in how much their patient can handle from one challenge to the next. If the patient is able to complete their challenge they are able to move on to the next stage of treatment, be it moving to an increased amount of allergen daily or the next step on their allergy ladder.

Overall the test can take several hours, so it's definitely worth taking toys, book or other entertainment with you.

This type of test is mostly used for respiratory affecting allergies, relating to Asthma or allergies that affect your lungs and airways. Mainly used for drug related allergies and food allergies, it can however be used for almost any other allergen.

The test involves the patient wearing a mask or mouthpieces and is hooked up to a machine and nebuliser. The machine measures and respiratory changes in the patient once exposed to the allergen. It may be reduced oxygen levels, increased histamine levels, addition tissue inflammation and more.

The patient is given an allergen a little at a time and if no reaction is visible, the amount of allergen is increased at 20-30 minute intervals, these might include chemicals, perfume or smoke, which commonly cause airway irritation.

This test helps specialists to understand how your lungs work when exposed to suspected allergens and is often used to see if a patient is suffering from an allergy of from Asthmas. Results tend to be provided at the appointment, however on occasion more than one test may be required.