Allergies are increasingly common in today’s world—affecting both children and adults. From seasonal sneezing and hives to life-threatening food reactions, allergies can vary in severity and cause. If your doctor suspects an allergy, one of the first diagnostic tools they may recommend is the IgE test.
In this comprehensive guide, we’ll break down everything you need to know about the Immunoglobulin E (IgE) test—including what it is, why it’s done, what it can detect, how to interpret the results, and what steps to take next.
What Is an IgE Test?
The IgE test is a blood test that measures the level of immunoglobulin E (IgE) in your bloodstream. IgE is a type of antibody produced by your immune system in response to allergens—substances your body mistakenly identifies as harmful.
There are two primary types of IgE tests:
Total IgE Test – Measures the overall level of IgE in your blood.
Specific IgE Test – Measures IgE levels in response to specific allergens, such as pollen, dust mites, certain foods, or pet dander.
Why Is the IgE Test Done?
Your doctor may order an IgE test if you show signs of:
Drug allergies
Anaphylaxis
It can also help identify triggers for allergic symptoms and monitor the effectiveness of allergy treatment.
How Does the Immune System Use IgE?
Your immune system typically produces antibodies to fight infections. But in some people, the immune system becomes overly sensitive and reacts to harmless substances (allergens) by producing IgE antibodies.
When you’re exposed to an allergen, these IgE antibodies trigger the release of histamines and other chemicals, leading to symptoms like:
Sneezing
Itching
Rashes
Wheezing
Swelling
In severe cases, anaphylaxis
The IgE test helps doctors determine whether an allergy is contributing to your symptoms.
When Should You Get an IgE Test?
Your doctor may recommend an IgE test if you experience:
Repeated sneezing, coughing, or wheezing, especially in specific environments
Frequent unexplained rashes or hives
Swelling of the face, lips, or throat
Gastrointestinal issues (bloating, diarrhea) after eating certain foods
Chronic skin conditions like eczema that worsen without obvious reason
Unexplained asthma flare-ups
In children, IgE testing is especially useful for identifying early food allergies or eczema triggers.
Types of IgE Tests: Total vs Specific
1. Total IgE Test
This test gives a general idea of the overall IgE level in the blood. It’s not specific to any allergen but can signal that your immune system is hyperactive.
High total IgE may indicate:
Allergies
Parasitic infections
Asthma
Atopic dermatitis
Some rare immune system disorders
Low total IgE usually rules out allergy-related conditions but doesn’t eliminate all possibilities.
2. Specific IgE Test (RAST or ImmunoCAP)
This test identifies the exact allergens causing your immune system to react. Blood is exposed to different allergens like:
Food (milk, eggs, peanuts, shellfish, wheat)
Inhalants (pollen, mold, dust mites, pet dander)
Insect venom (bee or wasp stings)
Medications (penicillin, aspirin)
A high IgE level to a specific allergen suggests you are sensitized to that allergen.
How Is the IgE Test Performed?
The IgE test is a simple blood test and usually involves the following steps:
A healthcare provider draws blood from a vein, usually in your arm.
The blood sample is sent to a laboratory.
Results are typically available within a few days.
No special preparation like fasting is usually required before the test.
What Do IgE Test Results Mean?
Understanding IgE test results involves interpreting whether total or specific IgE levels are high, low, or within normal range.
Total IgE Reference Range
| Age Group | Normal Range (IU/mL) |
|---|---|
| Newborns | <2 IU/mL |
| Children (1–5 yr) | <30 IU/mL |
| Children (6–12 yr) | <100 IU/mL |
| Adults | <150 IU/mL |
High Total IgE
May indicate:
Atopic conditions (eczema, asthma, hay fever)
Food or environmental allergies
Parasitic infections
Chronic infections (e.g., HIV)
Immune system disorders like Hyper-IgE syndrome
Normal or Low Total IgE
Doesn’t rule out allergies entirely
Some people with allergies have normal IgE levels
May suggest a non-IgE mediated allergy (delayed immune response)
Specific IgE Test Result Interpretation
Results are reported in classes, from 0 to 6:
| Class | kU/L Value | Interpretation |
|---|---|---|
| 0 | <0.35 | Negative / No allergy |
| 1 | 0.35 – 0.7 | Low sensitivity |
| 2 | 0.7 – 3.5 | Moderate sensitivity |
| 3 | 3.5 – 17.5 | High sensitivity |
| 4 | 17.5 – 50 | Very high sensitivity |
| 5 | 50 – 100 | Extremely high |
| 6 | >100 | Very strong allergenicity |
A high specific IgE result indicates sensitization, but this doesn’t always mean you’ll experience symptoms. Clinical correlation is necessary.
Benefits of IgE Testing
Identifies allergy triggers accurately
Helps in designing avoidance strategies
Guides immunotherapy or desensitization
Useful in children who cannot undergo skin prick tests
Safer for those with severe allergy history
Limitations of the IgE Test
False positives can occur—sensitization does not always mean allergy
False negatives possible in non-IgE mediated reactions
Cannot assess severity of an allergic reaction
Needs clinical correlation and possibly skin testing or food challenges
IgE Test vs Skin Prick Test
| Feature | IgE Test | Skin Prick Test |
|---|---|---|
| Invasiveness | Blood draw | Skin puncture |
| Risk of reaction | None | Mild to moderate local reaction |
| Suitable for | All ages, especially infants | Older children and adults |
| Detects | Sensitization (IgE antibodies) | Immediate allergic reactions |
| Medications affect? | No | Yes (antihistamines interfere) |
What to Do If Your IgE Is High
If your IgE test shows elevated levels:
Consult an allergist – further evaluation is essential.
Avoid known allergens – based on results.
Start treatment – may include antihistamines, corticosteroids, or immunotherapy.
Keep an allergy journal – to track triggers.
Retest if needed – especially in children, as allergies may change with age.
Treatment Options for Allergies
While an IgE test identifies allergens, treatment focuses on symptom relief and avoidance:
Antihistamines – for sneezing, itching, or rashes
Decongestants – for nasal symptoms
Inhalers – for asthma-related allergies
Epinephrine (EpiPen) – for anaphylactic reactions
Allergen immunotherapy – long-term solution via allergy shots or tablets
IgE and Chronic Conditions
1. Asthma
High IgE levels in asthma indicate allergic asthma, which is managed with inhalers and sometimes anti-IgE therapy.
2. Eczema
In atopic dermatitis, specific IgE tests help identify food or environmental triggers.
3. Hyper IgE Syndrome
A rare immunodeficiency where IgE levels are extremely high, often with frequent infections.
Anti-IgE Therapy
For patients with severe allergic asthma or chronic idiopathic urticaria, anti-IgE therapy using Omalizumab (Xolair) may be prescribed.
Binds free IgE and reduces allergic response
Administered via injection
Must be prescribed by a specialist
Why Choose Sparsh Diagnostic Centre for IgE Testing?
At Sparsh Diagnostic Centre, we offer:
✅ High-quality, accurate IgE testing
✅Home Sample Collection facility available
✅ Both total and specific IgE panels available
✅ Expert consultation with allergists and immunologists
✅ Fast turnaround times
✅ Affordable packages
✅ Clean, safe, and comfortable environment
📍 Open daily: Monday to Saturday – 7 AM to 9 PM | Sunday – 7 AM to 3 PM
📞 Call/WhatsApp: 9830117733 / 8335049501
🌐 www.sparshdiagnostica.com
Allergies can be disruptive—but they don’t have to control your life. The IgE test is a powerful diagnostic tool to pinpoint your allergens and guide effective treatment. Whether you suffer from seasonal sniffles, food reactions, or unexplained rashes, understanding your IgE levels is the first step to long-term relief.
If you suspect allergies, don’t wait. Book your IgE test at Sparsh Diagnostic Centre today and breathe easier tomorrow.
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Disclaimer:
No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.
