An allergy occurs when your immune system overreacts to typically harmless substances like pollen, dust, or pet dander. Symptoms can range from mild to severe in some cases.

1. Skin Tests: These involve applying small amounts of suspected allergens to the skin, typically via a prick, scratch, or injection (e.g. skin prick, intradermal, patch tests). A reaction, such as redness or swelling, indicates sensitivity to specific allergens.
2. Blood Tests: These measure markers of allergic response, such as antibodies and effector cell activation, after allergen exposure of the sample. Blood tests are used to avoid inherent risks from skin and oral allergy tests which may cause severe reactions.
3. Oral Food Challenges: This involves consuming small, controlled amounts of a suspected food allergen under medical supervision to observe any reactions. It’s considered the gold standard for diagnosing food allergies but is conducted in a highly controlled setting due to the risk of severe reactions.

Each test serves a specific purpose, no test is 100% accurate, and an allergist will determine the most appropriate based on the individual’s symptoms and medical history.

• Blood Tests: specific IgE (sIgE), total IgE (tIgE), Basophil Activation Test (BAT), Typtase
• Skin Prick Test & Intradermal Test: Detects immediate reactions; wheals appear within 15-20 minutes.
• Oral Food Challenge: Can trigger immediate symptoms (e.g., hives, swelling) during incremental dosing, typically within minutes to an hour.

• Blood Tests: Lymphocyte Transformation Test (LTT)
• Patch Test: Specifically designed to detect delayed reactions; patches are applied for 48 hours, with readings at 48-96 hours for redness or eczema.
• Oral Food Challenge: Rarely, delayed gastrointestinal or skin symptoms (e.g., eczema flare) may occur hours after ingestion.

Blood Allergy Test Risks

• No allergic reaction risk: Blood tests involve a simple blood draw sent to a lab. Since no allergens are introduced, there’s no risk of anaphylaxis.
• Blood draw risks: generally safe, but in you may experience some local pain and discomfort, dizziness, or light bruising under the skin. In very rare cases there can be infections or nerve damage (e.g. tingling/numbness), such risks are minimized with proper technique, sterile equipment, and experienced personnel.
• False Positives/Negatives: May not always correlate with clinical symptoms, may require further testing.

Skin Allergy Test Risks

• Local Reactions / Discomfort: these are the most common, include itching, redness, or small welts (wheals) at the test site. These typically resolve within hours in skin prick and intradermal tests, but may persist for day in patch tests. Intradermal skin tests have larger local reactions and higher systemic allergic reaction risk compared to skin prick tests, and in patch tests prolonged contact may irritate sensitive skin or exacerbate conditions like eczema.
• Systemic Allergic Reactions: more rare but possible, include hives, nasal congestion, and in very rare cases anaphylactic shock in highly sensitive individuals.
• False Positives/Negatives: Can occur, leading to misdiagnosis or unnecessary dietary/lifestyle restrictions. Intradermal tests are more sensitive, but also have a higher chance of over-detecting allergies, leading to false positives in some cases.

Oral Food Challenge Risks

• Allergic Reactions: Highest risk, as allergens are ingested. Reactions can range from mild (itching, hives) to severe (anaphylaxis with breathing difficulty, throat swelling, or low blood pressure).
• Gastrointestinal Symptoms: Nausea, vomiting, abdominal pain, or diarrhea may occur during or after the challenge.
• Delayed Reactions: Some reactions may appear hours later, requiring extended monitoring.
• Psychological Stress: Anxiety or fear, especially in children or those with a history of severe reactions.
• False Negatives: If doses are insufficient or the allergen form differs (e.g., cooked vs. raw), the test may miss an allergy.

Allergy Blood Tests

• Duration: 5min, results in 2-7 days
• Breakdown: 5 minutes for the blood draw (may increase in difficult cases, children), sample is processed in the lab, results are typically sent within 2-5 days.
• Note: The in-office time is short, but you won’t get immediate results.

Skin Prick Test:

• Duration: About 20-40 minutes total.
• Breakdown: Preparation and application of allergens (5-10 minutes), waiting for reactions (15-20 minutes), and result interpretation (5-10 minutes).
• Note: Multiple allergens can be tested simultaneously, so the number of allergens doesn’t significantly extend time.

Intradermal Test:

• Duration: About 30-60 minutes.
• Breakdown: Injection of allergens (10-15 minutes, depending on number of tests), waiting for reactions (15-20 minutes), and result assessment (5-10 minutes).
• Note: Often used after skin prick tests, so total time may increase if combined.

Patch Test:

• Duration: 2-7 days for the full process.
• Breakdown:
• Day 1: Application of patches with allergens (15-30 minutes).
• 48 hours later: Patches removed, initial reading (10-15 minutes).
• 48-96 hours after removal (days 4-7): Follow-up reading for delayed reactions (10-15 minutes per visit).
• Note: Requires multiple visits to monitor delayed reactions.

Oral Food Challenge:

• Duration: 2-4 hours, sometimes longer.
• Breakdown: Incremental ingestion of the allergen (30-60 minutes, with doses every 15-30 minutes), observation for reactions (1-3 hours), and post-challenge monitoring (30-60 minutes).
• Note: Time varies based on the protocol and whether reactions occur. Severe reaction history may extend observation.

StArtBio Blood Allergy Tests

*Indicative cost, prices for Allergy Tests on the website are not updated in real time. Call us for possible offers and test packages.

Useful Links: Allergology & Clinical Immunology Unit

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• We specialize in Allergy Diagnosis.
• Regularly used by Allergists.
• Fast and reliable results.
• No appointment required (except for children).