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Discover the Root of Allergies with a Simple Blood Test

Allergies are increasingly common among Thais, largely due to environmental factors like pollution and dust, which significantly elevate the risk of allergic reactions. Leaving untreated, allergies can disrupt daily activities, impacting work and studies, and even leading to daytime drowsiness caused by poor sleep quality.

Dr. Pakjira Naksen, a specialist in rhinology and allergies at Vejthani Hospital, explained that allergies result from the immune system reacting to foreign substances known as allergens, which are often protein-based. Allergies can be inherited or influenced by environmental factors such as dust, dust mites, pets, cockroaches, and cigarette smoke. Additionally, certain food can trigger allergies, such as seafood, cow’s milk, eggs, wheat flour, and peanuts. Symptoms and severity vary among individuals, depending on the type of allergen and how the body responses.

Allergies can affect multiple systems in the body

Respiratory allergies are caused by allergic rhinitis, resulting in symptoms such as nasal congestion, runny nose, sneezing. It can also lead to asthma, coughing, chest tightness, fatigue, shortness of breath, and wheezing.
Food and drug allergies can cause hives, facial or lip swelling, throat tightness, chest tightness, fainting, low blood pressure, and even life-threatening conditions.
Skin allergies can cause persistent red, itchy rashes accompanied by dry, peeling skin. These symptoms often appear in areas such as the creases of the arms, legs, and around the neck.
Eye allergies can lead to conjunctivitis, causing symptoms such as itchy eyes, eye irritation, redness, frequent eye rubbing, and swollen eyes.

Two Methods for Detecting Allergens

Skin prick test: This involves applying allergen extracts from various substances to the patient’s skin to determine which allergens cause a reaction. Common allergens tested include pet dander, dust mites, cockroaches, and grass pollen.
Serum Specific IgE: This method tests for allergens by analyzing blood. A blood sample is collected to detect immune responses to specific allergens, such as milk, nuts, seafood, animal dander, and fungi. The sample is sent to a laboratory, and the results typically take about 7 days. Unlike the skin prick test, patients do not need to stop taking antihistamines before the blood test. A single blood draw can identify multiple allergens with high precision and specificity.

Blood test is particularly suitable for:

People with severe dermatitis or dermatographism.
People with a history of severe allergic reactions to suspected allergens, such as food or substances previously causing “acute anaphylaxis,” as skin prick testing might provoke symptoms during the test, making the blood test a safer option.
Patients requiring continuous antihistamine medication who cannot discontinue it for seven days.
Infants under six months of age.

Once the doctor identifies the cause of the allergy, treatment will be provided based on the symptoms. This includes advising patients to avoid allergens and maintain overall health, such as eating a balanced diet included five food groups, exercising regularly, and getting sufficient sleep. Treatment may involve medications based on symptoms, such as antihistamines to treat itchy rashes, decongestants, and bronchodilators to treat shortness of breath or chest tightness. Additionally, allergy vaccination or allergy shots may be recommended, which involves injecting small amounts of allergens into the body and gradually increasing the dosage until the body becomes tolerant to them. Once the body becomes tolerant to the allergen, future exposure may not trigger symptoms. If a patient responds well to allergy vaccination, they may no longer need other medications.

Nonetheless, allergies are common diseases that can affect everyone. If you notice symptoms that may indicate an allergy, get tested to identify the cause and receive accurate treatment for a better quality of life.