Allergy Screening Programs for Children

• Respiratory Allergies (the most commonly diagnosed allergy type): Symptoms range from a runny nose, sneezing, itchy nose and nasal congestion (often referred to as allergic rhinitis) to more severe symptoms like coughing, chest tightness and shortness of breath, which are characteristic of asthma. Respiratory allergies are primarily caused by airborne allergens. In Thailand, dust mites are the most common trigger, followed by cockroaches, pet dander, and airborne molds.
• Skin Allergies: These include hives, eczema (atopic dermatitis) and contact dermatitis. Hives are often triggered by foods, medications or infections. Eczema, commonly seen in children with a family history of allergies, can also be triggered by food allergens such as cow’s milk or eggs, causing rashes on the cheeks in infants or in the creases of elbows and knees in older children.
• Gastrointestinal Food Allergies: Symptoms include abdominal pain, vomiting and mucus or blood in the stool. The main cause of gastrointestinal food allergies is food sensitivity.
• Systemic Reactions (often severe): In some cases, allergic reactions can affect multiple systems in the body, leading to severe symptoms such as shortness of breath, hives, anaphylactic shock and even death. These reactions may occur after consuming certain foods, like shrimp or peanuts, or after taking medications, such as penicillin.

• Genetics: Genetics play a role in many allergic conditions, such as asthma, allergic rhinitis, and atopic dermatitis in children. The likelihood of developing allergies is higher if there is a family history, especially if both parents have allergies. If one parent has an allergy, the child’s risk of developing an allergy is about 30-50%. If both parents have allergies, this risk increases to 50-70%. In contrast, children from families with no history of allergies have only a 10% chance of developing allergies.
• Environment: Environmental factors play a significant role, as allergens enter the body through breathing, ingestion or skin contact. Some allergens are easily recognizable; for example, eating seafood may cause hives within 30 minutes, or taking certain medications may result in a rash. Other reactions include sneezing, nasal congestion or asthma symptoms after activities such as cleaning the house or playing with cats or dogs.

• Respiratory Symptoms: Sneezing, itchy nose, runny nose, nasal congestion, itchy eyes, itchy throat, or a persistent cough with phlegm. Severe symptoms may include wheezing or shortness of breath. Symptoms can be seasonal, intermittent or year-round, depending on the severity and cause.
• Skin Symptoms: Hives, or itchy rashes in the creases of elbows and knees. In children, red rashes may appear on the cheeks.
• Gastrointestinal Symptoms: Nausea, vomiting, diarrhea, abdominal pain or bloody mucus in stools.
• Severe Allergic Reactions: In some cases, severe allergies can affect multiple systems leading to shortness of breath, difficulty breathing, hives, shock or even life-threatening reactions.

To determine the appropriate allergy tests and diagnose, the doctor will take a detailed patient history, conduct a physical examination, and choose suitable tests to identify allergens for each individual. There are two primary diagnostic methods:

1. Skin Prick Test: This test checks for reactions to various allergens. A small needle is used to prick the skin, followed by applying suspected allergens on the skin's surface. Results are available within 15-20 minutes.
2. Blood Test for Specific IgE: This test measures specific IgE antibodies against allergens. A blood sample is taken and analyzed in a lab to identify the specific allergens causing the reaction. Results are typically available within 1-3 days.