Allergies occur when the immune system overreacts to harmless substances, called allergens, mistaking them for threats. These allergens may be inhaled, ingested, or come into contact with the skin. The immune system responds by producing antibodies, which trigger inflammation in the skin, airways, sinuses, or digestive tract. Symptoms can range from mild issues like rashes, sneezing, or runny nose to severe reactions such as swelling of the throat or even life-threatening anaphylaxis. Common triggers include foods like peanuts, milk, and seafood, as well as airborne particles such as pollen, dust mites, and pet hair. Since most allergies cannot be cured, management focuses on identifying and avoiding triggers, along with having a clear action plan for flare-ups. Allergy testing plays a key role in this process, helping identify specific allergens so that patients can take preventive measures and reduce the risk of serious reactions, while maintaining a better quality of life.
An allergy is an overreaction by the immune system to a foreign substance it has detected inside the body. The foreign substance is called an allergen. The allergen may have been touched by the skin, inhaled or eaten. The immune system thinks the substance is dangerous and reacts accordingly. This can cause uncomfortable symptoms like skin rashes, a runny nose or sneezing. In more extreme cases, it can cause the throat to swell to the point where it becomes difficult to breathe or anaphylactic shock. Some allergies take a couple of hours to produce symptoms, while some allergies cause a severe life-threatening reaction within seconds.
Almost anything can trigger an allergy. Common allergens include foods like peanuts, soy, milk and seafood. People can also be allergic to common airborne particles like dust mites, seasonal pollen, mold spores and pet hair. When the allergy is triggered, the immune system makes antibodies that mark that specific substance as dangerous. When you come in contact with the allergen next time, the immune system promptly triggers the production of the antibodies, causing inflammation to the skin, sinuses, airways or digestive tract.
Most allergies can’t be “cured”. Instead, we put in place a management plan to ensure that the patient can live their life without too much discomfort from the allergy. The main strategy is avoiding the allergen. We also devise a plan of action for when the allergy is triggered, ensuring the patient can execute it as fast as possible. However, in order to do this, we first need to identify the allergen.
The Allergy Test is an important diagnostic tool to help identify a patient’s allergic triggers, I.e. which substances they are allergic to. It is performed by an allergist. Allergy tests expose the patient’s immune system to a number of known allergens in a controlled, safe environment and record the immune system’s reaction. There are 3 primary ways allergens can trigger an immune response:
Contact Allergens – These trigger an allergy when they come in contact with the skin. Synthetic fibers, certain fragrances in a perfume or metals found in jewellery can trigger a contact allergy.
Inhaled Allergens – These allergens are inhaled through the nose or mouth. The allergy is triggered once the substance comes in contact with the mucous membranes inside the nose, throat or lungs.
Ingested Allergens – These are allergens present in food. Food allergies can be triggered immediately, as soon as the food touches the lips. However, it could also be triggered after a few hours, once partially digested.
Different types of allergy tests are conducted to get a holistic picture of what a patient may be allergic to. In general, diagnosing contact allergens and inhaled allergens is straightforward, but diagnosing food allergies may require additional testing. This is because digestion is a complex process, and the allergy could be triggered at a specific step in the digestive tract.
A good candidate for allergy testing is a patient with persistent, unexplained symptoms like sneezing, itching, rashes, breathing difficulty, or inflammation. Usually, your family doctor or general physician will send you for allergy testing if they suspect your symptoms are caused by an allergic reaction, or to rule out the possibility of an allergy. This includes patients with suspected drug allergies and patients who are not responding well to their asthma medication. Both children and adults are eligible for allergy testing.
There are different types of allergy tests, designed to test for various allergens. Based on your symptoms and the suspected allergen, your immunologist will recommend the appropriate type of test for you:
Allergy Skin Test – This test is used to check for common environmental and food allergies. There are 2 levels of testing – Skin prick test, followed by an intradermal skin test. To conduct the skin prick test, your allergist will prick your skin (usually on the forearm) and then place a drop of a solution that contains a specific allergen on it. The prick is left alone for 15 minutes, after which the doctor checks for a reaction. Swelling and redness around the skin prick are usually signs of an allergy. The intradermal test is the next level of testing – In this test, a drop of the allergen solution is injected into the skin and left for 15 minutes. The immunologist checks the injection site after that, to determine if the patient has had an allergic reaction. The allergy skin tests are not painful, and usually only cause mild, momentary discomfort.
Patch Test – This is a non-invasive test used to check for an allergic trigger that causes contact dermatitis. The allergen being tested for is usually a contact allergen. A solution of the suspected allergen is applied to a patch and then stuck on the patient’s skin for 48 hours with hypoallergenic tape. Multiple patches are usually applied at the same time, to test for a panel of allergens. The patches are checked at specific times, and the skin’s condition is recorded. An eczema-like rash is usually a sign that the patient is allergic to that substance.
Blood Tests – Blood tests can also be used to check for an allergic reaction. Allergen specific IgE (Immunoglobulin E) testing can provide data about which allergen is causing an immune response, by measuring the levels of antibodies in the blood that attack that allergen. The blood test is performed in situations where skin testing isn’t practically feasible.
Oral Food Testing – This is a test performed in few cases, to confirm if a patient is actually allergic to a certain food. The patient is given a minute dose of the suspected food to eat. If the patient is able to tolerate the minute dose, they may subsequently be given incremental doses and kept under observation. Their reactions are recorded to determine if they have an allergy. It is important to note that this is done under controlled circumstances, and under a doctor’s careful supervision only. In case the allergy is triggered, the patient can be given an antihistamine immediately to stop them from going into anaphylactic shock.
If you suspect allergies are affecting your daily life, timely testing and expert guidance can make a significant difference. Kauvery Hospital, with branches in Chennai, Hosur, Salem, Tirunelveli, and Trichy, offers comprehensive allergy testing and personalised care to help you identify triggers, prevent reactions, and manage allergies safely and effectively.
How does allergy test help patients?
Allergy testing identifies specific substances that trigger allergic reactions, helping patients avoid allergens and manage symptoms effectively.
What symptoms indicate the need for allergy testing?
Persistent sneezing, itching, rashes, breathing difficulty, inflammation, or unexplained reactions may require allergy testing.
Can allergy testing prevent severe reactions?
Yes. Knowing your triggers allows you to avoid exposure and follow an action plan to reduce the risk of severe reactions like anaphylaxis.
Who can undergo allergy testing?
Both children and adults can undergo allergy testing, especially those with suspected allergies, asthma not responding to treatment, or drug reactions.
What types of allergens can be identified through testing?
Allergy testing can identify contact allergens, inhaled allergens like dust or pollen, and ingested allergens such as food.
What are the different types of allergy tests available?
Common tests include skin prick tests, intradermal tests, patch tests, blood tests, and oral food testing under medical supervision.
Is allergy testing safe?
Yes. Allergy tests are performed in controlled environments by specialists, with close monitoring and immediate treatment if a reaction occurs.
Kauvery Hospital is globally known for its multidisciplinary services at all its Centers of Excellence, and for its comprehensive, Avant-Grade technology, especially in diagnostics and remedial care in heart diseases, transplantation, vascular and neurosciences medicine. Located in the heart of Trichy (Tennur, Royal Road and Alexandria Road (Cantonment), Chennai (Alwarpet, Radial Road & Vadapalani), Hosur, Salem, Tirunelveli and Bengaluru, the hospital also renders adult and paediatric trauma care.
Chennai Alwarpet – 044 4000 6000 • Chennai Radial Road – 044 6111 6111 • Chennai Vadapalani – 044 4000 6000 • Trichy – Cantonment – 0431 4077777 • Trichy – Heartcity – 0431 4077777 • Trichy – Tennur – 0431 4022555 • Maa Kauvery Trichy – 0431 4077777 • Kauvery Cancer Institute, Trichy – 0431 4077777 • Hosur – 04344 272727 • Salem – 0427 2677777 • Tirunelveli – 0462 4006000 • Bengaluru – 080 6801 68011
