HSA | FSA CARDS ARE NOW ACCEPTED

Last reviewed: May 12, 2026 Last updated: May 12, 2026

Written by: Jay Hastings , CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance. His work has included scaling healthcare startups, leading CLIA lab integrations, and helping expand consumer access to precision health tools.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

Understanding Hay Fever and the IL33 Gene

Hay fever, also called allergic rhinitis, is an immune reaction that causes sneezing, runny nose, nasal congestion, itchy or watery eyes, and sometimes throat irritation. These symptoms occur when the immune system reacts to common environmental allergens such as pollen, pet dander, dust mites, or mold.

The IL33 gene makes interleukin-33, a signaling protein sometimes called an immune "alarmin." When airway cells are stressed by allergens, IL-33 is released and helps activate immune cells that drive type 2 helper T cell, or Th2, responses. Overactivity of this pathway can lead to the inflammation and symptoms associated with hay fever and related conditions like asthma. Variations in the IL33 gene can change how strongly this system responds, influencing an individual’s susceptibility to allergic inflammation.

What Your Genotype Means

Below are easy-to-read interpretations based on the rs928413 variant in IL33. Use the accordion to view the explanation that matches your genotype.

Two effect alleles (GG)

If your genotype is GG, you carry two copies of the effect allele for rs928413. This variant is associated with an increased risk of hay fever and asthma. Mechanistically, the change is linked to heightened IL-33 activity or signaling, which can amplify Th2-type immune responses when the airways encounter allergens like pollen, dust mites, or pet dander.

Practical implications:

  • You may be more likely to experience strong allergic symptoms and inflammation after allergen exposure.
  • Allergen avoidance and early management are especially helpful to reduce episodes and prevent escalation to asthma-like symptoms.
  • Targeted strategies to calm Th2 inflammation and stabilize mast cell responses can reduce symptom frequency and severity.
One effect allele (AG)

If your genotype is AG, you carry one copy of the effect allele. This genotype is associated with a modestly increased risk of hay fever and asthma compared with the baseline population risk. The IL-33 pathway may be somewhat more reactive, which can make allergic inflammation more likely under triggering conditions.

Practical implications:

  • You may notice seasonal or intermittent allergic symptoms, particularly during high-pollen seasons or when exposed to indoor allergens.
  • Combining allergen reduction with supportive lifestyle and nutritional measures can meaningfully reduce symptom burden.
No effect alleles (AA)

If your genotype is AA, you do not carry the G effect allele linked to increased IL33-related risk. Your IL-33 driven allergic risk is within the typical range for the general population. This does not eliminate the possibility of hay fever from other genetic factors or environmental exposures, but it suggests IL33 is not a primary driver of elevated risk in your case.

Practical implications:

  • Standard measures such as allergen avoidance, good nasal hygiene, and targeted nutrients often work well to control symptoms.
  • If symptoms are severe or persistent, further evaluation for other genetic or environmental causes may be helpful.

Diet and Nutrition Strategies

A nutrient-rich diet can support a balanced immune response and reduce overall inflammation that contributes to allergic symptoms.

  • Eat a variety of colorful fruits and vegetables to boost antioxidants and vitamin C. Citrus, berries, kiwi, bell peppers, and leafy greens are particularly helpful.
  • Include omega-3 rich foods such as fatty fish, chia seeds, flaxseed, and walnuts to support anti-inflammatory pathways.
  • Increase natural quercetin-containing foods like onions, apples, capers, and berries. Quercetin is a plant flavonoid known to stabilize mast cells and reduce histamine release.
  • Choose fermented foods like yogurt, kefir, sauerkraut, kimchi, and miso to support gut microbial balance, which is linked to immune regulation.
  • Limit highly processed foods, excess added sugars, and trans fats that can promote systemic inflammation.

Supplement Considerations

Supplements can complement diet and lifestyle when used appropriately. Discuss these options with your healthcare provider.

  • Vitamin C: A natural antioxidant that may reduce histamine levels and support immune health. Typical supplemental doses range from 250 to 1,000 mg daily depending on needs.
  • Quercetin: A bioflavonoid that helps stabilize mast cells and may reduce allergic symptoms. Common supplemental doses are 250 to 500 mg two to three times daily with meals.
  • Probiotics: Strains such as Lactobacillus and Bifidobacterium can support a healthier gut-immune axis. Choose a well-characterized product with adequate colony-forming units (CFUs) and strain information.
  • Omega-3 fatty acids (EPA/DHA): Fish oil supplements can help reduce inflammation; typical ranges are 500 to 1,000 mg combined EPA/DHA daily for maintenance.
  • Vitamin D: Supports immune regulation. Check blood levels before supplementing; many benefit from moderate supplementation if levels are low.

Lifestyle and Environmental Tips

  • Allergen avoidance: Close windows during high-pollen times, use HEPA filters or air purifiers, and keep indoor humidity between 30 and 50 percent to reduce dust mites and mold.
  • Nasal hygiene: Saline nasal rinses or sprays help remove allergens and reduce nasal inflammation.
  • Pet management: If pet dander triggers symptoms, restrict pets from bedrooms and wash hands after stroking animals. Regular bathing of pets can reduce dander.
  • Cleaning routine: Frequent vacuuming with a HEPA-filter vacuum and washing bedding in hot water weekly reduce indoor allergen load.
  • Exercise: Regular moderate exercise supports immune balance and respiratory health, but avoid outdoor workouts during peak pollen counts.
  • Hydration and sleep: Adequate fluids and good sleep support immune resilience and recovery from inflammatory episodes.

When to Seek Additional Testing or Care

  • If symptoms are severe, persistent, or interfering with daily life, consult a healthcare professional for evaluation and treatment options.
  • Allergy testing may identify specific allergens to target avoidance or immunotherapy.
  • Work with your provider to review medication choices, including antihistamines, intranasal corticosteroids, or other prescribed therapies when needed.

Important Disclaimer

PlexusDx provides educational information about genetic predispositions only. This content is not medical advice. Always consult your healthcare provider before starting, stopping, or changing diet, supplements, medications, or lifestyle practices based on genetic information.

If this genetic variant is present in your PlexusDx results, the following tests and reports are commonly used to explore it further:

🧬 Genetic Tests:

🧪 Blood Tests:

📄 Genetic Report:

Frequently Asked Questions About Hay Fever and IL33 rs928413

What does the IL33 rs928413 variant mean for my hay fever risk?

The IL33 gene helps produce interleukin-33, an immune “alarmin” that becomes active when airway cells are stressed by allergens. Changes in IL33 can affect how strongly this pathway drives type 2 (Th2) immune responses, which are linked to allergic inflammation. Depending on your IL33 rs928413 genotype (AA, AG, or GG), your susceptibility to hay fever and asthma-like inflammation may be increased or within the typical population range.

How do different IL33 rs928413 genotypes (GG, AG, AA) affect symptoms?

GG: Associated with an increased risk of hay fever and asthma, likely due to heightened IL-33 activity that amplifies Th2 responses after allergen exposure (pollen, dust mites, pet dander). AG: Associated with a modestly increased risk versus baseline, with a somewhat more reactive pathway under triggering conditions. AA: No effect allele tied to increased IL33-related risk, suggesting your risk from IL33 is within the typical range (though hay fever can still occur from other genetic factors and environmental exposures).

What diet, supplements, and lifestyle strategies can help manage IL33-related allergic inflammation?

Support a balanced immune response by eating antioxidant- and anti-inflammatory foods: colorful fruits/vegetables (vitamin C-rich options), omega-3 sources (fatty fish, chia, flax, walnuts), quercetin-rich foods (onions, apples, capers, berries), and fermented foods (yogurt, kefir, sauerkraut, kimchi, miso). Consider supplements such as vitamin C, quercetin, probiotics (Lactobacillus/Bifidobacterium strains), omega-3 (EPA/DHA), and vitamin D—ideally discussed with your healthcare provider. Pair nutrition with allergen and environmental controls (HEPA/air purification, humidity 30–50%, saline nasal rinses, HEPA vacuuming, regular bedding washing, pet bedroom restrictions if needed) and maintain healthy sleep and hydration; seek medical care if symptoms are severe, persistent, or disruptive.

What tests can help me learn more about Hay Fever and IL33 rs928413?

The Food Sensitivity & Allergy Genetic Test analyzes over 240 genetic insights related to immune response, inflammation, and dietary tolerance. The Allergies and Food Sensitivities Genetic Report translates your results into personalized, actionable guidance. Your healthcare provider can also recommend targeted blood tests based on your specific pathway results and health history to complement your genetic insights with current biomarker data.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance. References are included at the end of the article when scientific, medical, or health-related claims are discussed.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.