Allergy Test: Which Blood Test Finds Your Triggers — IgE, Allergy Panels and Eosinophils Explained

Quick answer: Allergy blood tests measure IgE antibodies. Total IgE shows a general allergic tendency; specific IgE panels test reactions to individual allergens such as dust mites, pollens, moulds, pet dander, cockroach and foods. A CBC with absolute eosinophil count supports an allergic cause. These tests are useful for persistent sneezing or blocked nose, asthma, eczema or hives, and suspected food allergy. A positive result shows sensitisation, which must be matched with your symptoms by a doctor — not every positive means you will react.

Gurugram's air brings a mix of triggers: construction and road dust, vehicle pollution, seasonal pollen (especially in spring and after the monsoon), indoor dust mites thriving in humid months, and moulds in air-conditioned homes. Many people live with "constant cold" symptoms for years without realising they are allergic.

Symptoms That Suggest Allergy

Nose and Eyes (Allergic Rhinitis)

• Sneezing fits, especially in the morning
• Runny or blocked nose, itchy nose and throat
• Itchy, watery eyes
• Symptoms that worsen in certain seasons, rooms or around pets

Chest (Allergic Asthma)

• Wheezing, chest tightness, cough — often at night or with exercise
• See smog season lung tests and PFT test

Skin

• Eczema — dry, itchy, inflamed patches
• Hives (urticaria) — raised, itchy welts

Food Allergy

• Hives, lip or tongue swelling, vomiting or abdominal pain soon after eating
• Severe reactions (anaphylaxis) — breathing difficulty, throat tightness, dizziness — are emergencies

Allergy Blood Tests Explained

Total IgE

A raised total IgE suggests an allergic tendency, but it doesn't tell you what you're allergic to. It can also be raised in worm infections and some other conditions.

Specific IgE Panels

Measure IgE against individual allergens. Common panels include:

• Inhalant panel: house dust mites, pollens (grasses, trees, weeds), moulds, cockroach, cat and dog dander
• Food panel: milk, egg, wheat, peanut, soy, fish, shellfish, nuts and others
• Combined panels for people with mixed symptoms

Results are reported in classes or levels — higher levels generally mean stronger sensitisation.

CBC With Absolute Eosinophil Count (AEC)

Eosinophils are white cells that rise in allergies and asthma (and parasitic infections). See CBC explained.

Blood Tests vs Skin Prick Tests

• Blood tests can be done regardless of antihistamine use and skin condition, and carry no risk of reaction
• Skin prick tests are done by allergy specialists and give quick results, but require stopping antihistamines beforehand

Both detect sensitisation, and both need interpretation with your history.

Important: Positive Doesn't Always Mean Allergic

Many people have IgE to an allergen but no symptoms when exposed. That's why your doctor matches results with your history — for example, a dust mite positive in someone whose symptoms are worse in bedrooms and in the monsoon is meaningful; a peanut positive in someone who eats peanuts without problems may not be. Never remove major foods from a child's diet based on a blood test alone — consult a doctor.

Who Should Get Tested?

• Persistent or seasonal nasal symptoms despite treatment
• Asthma, especially if poorly controlled
• Eczema or chronic hives
• Suspected food allergy
• Before starting allergen immunotherapy, as advised by a specialist

Reducing Common Allergen Exposure at Home

• Dust mites: wash bedding weekly in hot water, use mite-proof covers, reduce soft toys and carpets in bedrooms
• Moulds: fix damp spots, clean AC filters regularly, use exhaust fans
• Pollen: keep windows closed on high-pollen days, shower after outdoor activity
• Pets: keep them out of bedrooms
• Pollution: use air purifiers and N95 masks on high-AQI days

Frequently Asked Questions

Which blood test is done for allergy?

Total IgE shows allergic tendency, and specific IgE panels identify individual triggers such as dust mites, pollens, moulds, pet dander and foods. A CBC with eosinophil count also helps.

Do I need to stop antihistamines before an allergy blood test?

No. Allergy blood tests are not affected by antihistamines, unlike skin prick tests.

Is fasting needed for allergy tests?

No. Allergy blood tests do not require fasting.

Can an allergy test be positive without symptoms?

Yes. A positive test shows sensitisation, but not everyone who is sensitised has symptoms. Results must be interpreted with your history.

What are the most common allergies in Gurugram?

House dust mites, pollens, moulds, pet dander and cockroach are common inhalant triggers, with pollution worsening symptoms.

How long do allergy test results take?

Specific IgE panels typically take one to three days depending on the panel. Total IgE and CBC are usually faster.

Book an Allergy Test in Gurugram

Find out what's really behind your symptoms. Book total IgE, allergy panels and eosinophil count at our Sector 67 lab or with home sample collection. Call +91 92663 33711. See our immunology tests.

This article is for general information only. Severe allergic reactions are emergencies — seek immediate medical care.