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What Is an Allergy?
An allergy occurs when the body’s immune system abnormally reacts to a substance that typically does not cause a reaction in most people. These substances are known as allergens. When exposed to an allergen, the immune system identifies it as a threat and triggers a response, leading to symptoms such as sneezing, itching, swelling, and in severe cases, anaphylaxis.
An allergy is a relatively common condition. Some people are more susceptible to allergies, and hereditary and environmental factors contribute to allergy development. However, although specific allergies are not hereditary, the likelihood of developing one considerably increases if family members have allergies.
Common allergens
Substances that trigger allergic responses are called allergens.
Below is the list of common allergens:
- Tree and grass pollen
- Animal fur
- Food like fruit, nuts, shellfish, eggs
- Insect bites and stings
- Medications (certain antibiotics)
- Latex
- Household chemicals like hair dyes and detergents
Symptoms of an allergy
Allergy symptoms can significantly vary depending on the allergen that is involved. An allergy can affect your digestive system, skin, nasal passages, airways, and sinuses.
Allergic reactions can range from mild to severe. In severe cases, it can also cause a life-threatening reaction known as anaphylaxis.
Below is the list of symptoms of an allergy based on the type of allergen.
1. Allergic rhinitis (hay fever caused by grass and tree pollen):
- Runny nose
- Sneezing
- Itchy eyes and nose
- Swollen, red and watery eyes
2. Allergic reactions to certain foods:
- Hives (raised, red and itchy rash)
- Shortness of breath
- Dizziness
- Nausea or vomiting
- Abdominal pain
- Diarrhoea
- Swelling of the throat, face, lips, or other parts of the body
- Allergic rhinitis symptom
3. Allergic reaction to certain medications:
- Itching
- Hives
- Wheezing or shortness of breath
- Anaphylaxis
- Swelling
4. Allergic reaction to insects:
- Hives
- Itching
- Swelling around the sting area
- Shortness of breath, coughing, tightness in the chest, wheezing
- Dizziness
- Vomiting
5. Skin allergies:
- Flaking of skin
- Redness
- Itching
- Rashes
- Bumps
Anaphylaxis
Symptoms of a severe allergic reaction, also known as anaphylaxis, can develop suddenly and rapidly. The initial symptoms of anaphylaxis are mostly identical to those listed above. However, it might result in the following conditions:
- Breathing difficulties
- Swollen mouth and throat
- Chest tightness
- Dizziness
- Loss of consciousness
Anaphylaxis is a life-threatening condition that requires immediate medical attention. If you or someone you know appears to be suffering from anaphylaxis, call for an ambulance immediately because anaphylaxis can be fatal if it goes untreated.
Types of allergy tests
An allergy test is conducted to investigate the type of allergen an individual has reactions to. The tests that can be performed include:
1. Skin Prick Test
In this method, droplets of allergens are placed on your forearm. A medical device is used to gently prick the area. Within 15 minutes, an itchy, red bump will emerge on the skin if you are allergic to the substance.
2. Blood Test
Blood tests may be used in place of or in addition to skin prick testing to aid in diagnosing common allergies. Particular allergens are added to the blood, and the level of antibodies produced by your immune system is evaluated. You are likely to be allergic to the substance if large amounts of antibodies are produced for a particular allergen.
3. Intradermal Skin Test
A small amount of allergen will be injected into the skin. If the injected area shows any reaction, the individual has an allergy.
4. Skin Patch Test
Allergens applied to adhesive patches are placed on the skin. The patches are reviewed after the 48th and 96th hour of placing them. Swimming and other activities that generate a lot of perspiration should be avoided during this period. When you return to the doctor's office, the patches are removed. The patch location may be irritated, which could indicate an allergy.
Allergy tests FAQs
1. Does it hurt when the allergy test is done?
Although some individuals find the tests uncomfortable, they are generally not considered to be extremely unpleasant. Nevertheless, they are a highly safe procedure.
2. Can allergies be detected via a blood test?
Blood tests are the most effective way to detect allergies. Allergens are added to the blood, and the level of antibodies produced by your immune system is evaluated. If large amounts of antibodies are produced for a particular allergen, you will likely be allergic to the substance.
3. Will I feel sick after doing an allergy test?
The commonly known side effect is the test site’s redness, swelling or itching. Most temporary symptoms will resolve within a few hours after the test. However, if the allergic reaction remains beyond the expected hours, expert medical help is needed.
4. What are the most common types of allergens?
- Tree and grass pollen
- Animal fur
- Food like fruit, nuts, shellfish, eggs
- Insect bites and stings
- Medications (certain antibiotics)
- Latex
- Household chemicals like hair dyes and detergents
5. Am I allowed to eat before an allergy test?
Yes, you can have regular food before an allergy test. However, it is better to refrain from any food items that have caused an allergy in the past or those you suspect to have an allergy from.
6. How do I know if I need an allergy test?
Anyone can take the test. However, an allergy test is highly recommended if you consistently have any of the symptoms mentioned above.
Make an appointment at Gleneagles Hospitals
Allergy tests are highly beneficial for finding the substance that causes an adverse reaction in your body. While some people have mild allergies, others can even have a life-threatening reaction. Therefore, knowing the exact substances you are allergic to is advisable to stay safe.
Contact us to book an appointment with the Allergy and Immunology specialists at Gleneagles Hospital for more information on allergy tests.