The Role of IgE Levels in Diagnosing and Managing Eczema

Several types of eczema are associated with allergic sensitization. Numerous studies have documented that individuals with eczema are at a heightened risk for developing food allergies, for example.

For anyone who has battled the relentless itch and flare-ups of eczema, the connection between skin inflammation and allergies can feel undeniable. However, identifying allergic triggers can be more difficult than it sounds. Solutions for better eczema control may lie in immunoglobulin E (IgE).

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What Are IgE Levels?

Immunoglobulins, or antibodies, are proteins the immune system's B cells make to defend the body against foreign substances perceived as threats.

IgE is one of the five subsets of antibodies that protect the body against parasites and is responsible for initiating allergic reactions. When IgE binds to allergens, it triggers the release of inflammatory substances like histamines, leading to symptoms such as itching, swelling, and redness.

Elevated IgE levels are commonly seen in conditions associated with allergies, including asthma, allergic rhinitis (hay fever), and eczema – collectively called the "atopic triad."

Two types of eczema – atopic dermatitis (AD) and contact dermatitis – have a strong allergic component. Elevated IgE levels are found in approximately 80% of individuals with AD, making it the most common laboratory finding in this type of eczema.

How IgE Levels Are Measured

IgE levels can be measured through blood tests.

Total IgE tests, such as Immunoglobulin E by Access Med Labs, measure the overall amount of IgE antibodies in the blood. A high total IgE level can indicate an allergic predisposition but does not specify the allergens the immune system is reacting to.

Specific IgE tests measure the amount of IgE produced when your blood is exposed to an allergen. Elevated IgE levels indicate hypersensitivity to a particular allergen.

The radioallergosorbent test (RAST) detects specific IgE antibodies by exposing a patient's blood to allergens bound to a solid surface. If IgE antibodies are present, they bind to the allergens and are detected using radioactivity, with higher levels indicating stronger allergic reactions.
ImmunoCAP is the next generation of RAST. It uses fluorescence instead of radioactivity to detect specific IgE antibodies, making it a safer and more precise testing method.

These are examples of specific IgE tests that can be ordered through Rupa Health:

27 Food Panel: IgE by US BioTek
IgE Inhalants by Genova Diagnostics
295 Food & Inhalant IgE Allergy Panel by US BioTek

The Role of IgE in Diagnosing Eczema

Eczema is typically diagnosed based on the clinical presentation of the rash and the patient's history. Routine laboratory tests are usually unnecessary for diagnosis, but allergy testing (like IgE testing) may be considered if the diagnosis is uncertain or if the patient's eczema doesn't improve with first-line treatments, indicating the need for specialized care.

Elevated IgE levels are frequently found in patients with AD. Up to 80% of individuals with AD are sensitized to environmental and food allergens, and studies have demonstrated a direct correlation between total and specific IgE levels and AD severity.

Limitations and Considerations of IgE Testing in Eczema

Despite these associations, the American Academy of Dermatology (AAD) does not recommend routine measurement of serum IgE to diagnose eczema for several reasons:

Total IgE levels alone are nonspecific, meaning they can be elevated due to other causes, such as parasitic infection, certain cancers, and autoimmune diseases.
Elevated allergen-specific IgE levels are found in 55% of the United States general population, including individuals without eczema.
About 20% of patients with AD have normal IgE levels.
Certain forms of eczema, such as seborrheic dermatitis, may not involve IgE at all.

Blood allergy tests can result in false positives 50-60% of the time, so it is important to interpret their results alongside the patient's history and symptoms.

Skin prick tests (SPTs) are often preferred over allergy blood tests because they detect immediate allergic reactions more accurately. However, in cases where eczema is severe (making the skin difficult to test) or the patient is taking antihistamines (which can interfere with SPT results), doctors may recommend blood tests as a more practical alternative (3).

How IgE Levels Influence Eczema Management

When allergens are suspected triggers for eczema flares, understanding a patient's IgE levels can be instrumental in developing an effective eczema management plan. Identifying and eliminating allergen exposure can reduce IgE levels and significantly improve eczema symptoms and the frequency of flare-ups.

Common allergens associated with eczema include:

Dust mites
Pollen
Mold spores
Pet dander
Tree nuts
Peanuts
Milk
Eggs
Wheat
Soy
Fish

IgE test results can also guide targeted treatment recommendations for the eczema's allergic component. For example, antihistamines and corticosteroids are generic first-line treatment recommendations for eczema to reduce skin inflammation and bothersome eczema symptoms, such as severe itching.

However, powered by specific IgE allergy results, immunotherapy can be prescribed to desensitize the immune system to the identified allergens. According to a 2023 systematic review, subcutaneous and sublingual immunotherapy to aeroallergens, particularly dust mites, can improve AD severity and patient quality of life.

IgE Levels and Severe Eczema: What Research Shows

IgE plays a key role in initiating and maintaining inflammation in allergic diseases. IgE antibodies bind to immune cells called mast cells and basophils, triggering them to release pro-inflammatory substances. Persistent exposure to allergens can cause ongoing IgE-mediated inflammation, contributing to skin barrier dysfunction, chronic itching, and frequent flare-ups.

This is why elevated IgE levels are often associated with severe and persistent cases of eczema.

Recent advancements in eczema treatment focus on targeting the immune pathways associated with elevated IgE and inflammation. Biologic therapies, such as dupilumab, have emerged as game-changers in managing moderate to severe eczema. Dupilumab works by inhibiting interleukin-4 (IL-4) and interleukin-13 (IL-13), cytokines involved in the immune response that leads to elevated IgE production.

Clinical trials have shown that dupilumab provides rapid and sustained relief of moderate-to-severe AD in children, adolescents, and adults.

Practical Tips for Managing Eczema with IgE Insights

Begin integrating your IgE test results into a broader eczema strategy by following these tips:

Allergen-Proof Your Home

Vacuum and dust your home at least once a week
Wash bedding weekly in hot water
Use allergen-proof bed covers on pillows and mattresses
Invest in HEPA air purifiers for bedrooms and main living areas
Keep windows and doors closed during high pollen seasons
Remove your shoes before entering your home
Bathe and groom pets regularly to minimize shedding. Designate the bedrooms as pet-free zones. (13)

Dietary Modifications

40% of children with moderate-to-severe AD have been diagnosed with food allergies. Patients should work with their doctor or a nutritionist to implement an elimination diet when food allergies are diagnosed.

Additionally, an anti-inflammatory diet can help control the inflammation in eczema.

An excellent place to start is by avoiding:

Refined carbohydrates
Added sugars
Highly processed foods

Instead, focus on eating a whole-food diet rich in:

Whole fruits and vegetables
Legumes
Nuts and seeds
Lean proteins
Herbs and spices

Research suggests that omega-3 fatty acids, prebiotics, and probiotics have beneficial effects on eczema. As such, you could also include the following in your diet:

Fatty fish, such as salmon and sardines
Walnuts
Flaxseeds
Garlic and onions
Oats
Sauerkraut
Kimchi
Kombucha

Skin Barrier Care

Hydrate the skin by using emollient moisturizers regularly
Bathe in warm water instead of hot
Avoid using harsh soaps and irritating skin products
Avoid scratching the skin (12)

When to Consider IgE Testing for Eczema

IgE testing may be beneficial for patients with:

Persistent or poorly controlled eczema despite standard treatments
Frequent or unexplained eczema flare-ups
Suspected allergies that have not been confirmed (41)