Hazelnut Pollen Allergy Shots (SCIT)
Hazel pollen allergy shots (SCIT) treat inhalant sensitization to Cor a 1.01 — a PR-10 protein distinct from both the hazelnut kernel PR-10 isoform (Cor a 1.04, heat-labile OAS) and the anaphylactic kernel storage proteins (Cor a 8, Cor a 9, Cor a 14). No hazel-pollen-specific SCIT RCT exists; family-level evidence from Itulazax TT-04 (birch-homologous, 634 adults) supports the same immunotherapy target.
About Curex’s SCIT program
Curex’s at-home allergy shots (SCIT) are coming soon and focus on the most common environmental allergens:
- • Pollens — tree, grass, weed & ragweed
- • Pet dander — cat & dog
- • Dust mites
- • Molds — Alternaria & mold mix
Hazelnut Pollenis covered here for general education and may not be part of Curex’s current treatment set. Join the waitlist and our care team will help confirm your options.
Hazelnut Pollen Allergy Immunotherapy: How It Works
Allergy immunotherapy is the only long-term treatment that re-trains the immune system to stop overreacting to hazelnut pollen — rather than just masking symptoms with antihistamines or steroids. By gradually exposing the body to controlled doses of hazelnut pollen allergen, immunotherapy shifts the underlying allergic response and produces relief that often outlasts treatment by 7–10 years.
There are two evidence-based forms of hazelnut pollen immunotherapy used today, both built on the same desensitization principle but delivered very differently.
of sustained relief after a complete immunotherapy course — the only allergy treatment with proven long-term effect after stopping.
Allergy Shots (SCIT)
Weekly injections of hazelnut pollen extract in a clinic, escalating over 3–6 months until a maintenance dose is reached. Continued monthly for 3–5 years. Longest clinical track record for hazelnut pollen allergy.
- Strongest evidence base for severe and polysensitized patients
- Covered by most insurance plans
- Requires 50–100+ in-person clinic visits across the full course
- Or at home with no clinic visits— Curex’s Virtual Shot Room model delivers the same SCIT program with live video supervision by trained Curex clinical staff for the first injection from each new vial or concentration and restarts after gaps or reactions.
Allergy Drops / Tablets (SLIT)
Daily drops or dissolvable tablets containing hazelnut pollen extract, held under the tongue at home. Same desensitization principle, delivered without injections. WHO-recognized as an effective form of allergy immunotherapy since 2001.
- Taken at home — no weekly clinic trips, no needles
- Lower systemic reaction rate than allergy shots
- Curex offers prescription hazelnut pollen immunotherapy drops with allergist oversight
The rest of this page goes deep on allergen-specific immunotherapy with shots — protocol, efficacy data, side effects, and cost. If you’d rather skip the clinic and treat hazelnut pollen allergy with at-home drops, see how Curex sublingual immunotherapy compares below.
What is Hazelnut Pollen?
The biology, taxonomy, and clinical fingerprint of Hazelnut Pollen — the foundation of how SCIT targets it.
Corylus avellana catkins release pollen in late winter — the second-earliest Fagales allergen of the year, often co-pollinating with red alder in the PNW and with early birch in the Northeast. The pollen is the inhalant allergen; the kernel proteins are a separate allergy system.
- Scientific name
- Corylus avellana L. / C. americana Marshall
- Family
- Betulaceae (Corylaceae sensu lato)Birch family
- Type
- Deciduous shrub/tree pollen
- Native to
- C. avellana — Europe/western Asia (cultivated in Oregon, PNW); C. americana — eastern/central US native
- Allergen proteins
- Cor a 1 (major) — PR-10, ~17 kDa, ~67% identity with Bet v 1 (WHO/IUIS); two key isoforms: Cor a 1.01 (pollen, inhalant) and Cor a 1.04 (kernel, food-OAS PR-10)Cor a 2 — Profilin, pan-allergen (WHO/IUIS)NOTE — Kernel food allergens (NOT pollen, NOT treated by hazel pollen SCIT): Cor a 8 (9 kDa nsLTP, heat-stable), Cor a 9 (11S legumin, heat-stable), Cor a 14 (2S albumin, heat-stable)
- Particle size
- ~20–25 μm
- Avoidance difficulty
- Very difficult
How Hazelnut Pollen Allergy Presents
Symptoms by body system — useful for distinguishing Hazelnut Pollen sensitivity from overlapping allergies and infections.
Respiratory
- Sneezing and nasal discharge during late-winter catkin release — often January–March in the PNW and February–March in the Northeast
- Nasal congestion on high-pollen days when catkins shed en masse
- Itchy nose and post-nasal drip throughout the 4–6 week hazel pollen window
- Allergic asthma exacerbations in sensitized patients during peak season
- Worsening symptoms on warm, dry, windy days when pollen counts peak
Ocular
- Bilateral eye itching and conjunctival redness during hazel pollen season
- Watery discharge and eyelid swelling on high-pollen days
- Photophobia during severe conjunctival inflammation
- Periorbital puffiness, particularly in the morning
Dermal
- Oral allergy syndrome (OAS) via Cor a 1.01/1.04 PR-10 cross-reactivity: lip tingling, mouth itch, or mild throat itch after eating raw hazelnut kernel — heat-labile, resolved by roasting or cooking
- OAS to apple, peach, cherry, carrot, celery via broader Bet v 1 PR-10 spectrum
- Atopic dermatitis flares coinciding with hazel pollen season in sensitized patients
Systemic
- Fatigue from early-winter allergy that catches patients off guard before spring is on the calendar
- Sleep disruption from nighttime nasal congestion during hazel-pollen weeks
- Dietary anxiety from unclear OAS food triggers — patients unsure whether their hazelnut reaction is PR-10 OAS or anaphylactic storage-protein allergy
- Reduced quality of life during the late-winter pollen window
When a patient tells me they have 'hazelnut allergy,' my first question is what happens when they eat raw hazelnut versus roasted. PR-10 Cor a 1.04 OAS is heat-labile and usually benign. Cor a 9 storage-protein anaphylaxis is heat-stable and can be life-threatening. Hazel pollen SCIT can reduce the PR-10 cross-reaction, but it does absolutely nothing for storage-protein anaphylaxis — and confusing the two is dangerous.
When & Where Hazelnut Pollen Peaks
Allergen intensity by month and by state. Useful for timing SCIT start dates and travel planning.
12-Month Intensity
Peak: late January through March in the PNW; February–March in the Northeast — second-earliest Fagales after red alder· ~4–8 weeks; PNW hazel season often overlaps with red alder pollen release
US Exposure Map
2 high-intensity statesExposure intensity by state (text version)
- ME:
- Moderate
- VT:
- Moderate
- NH:
- Moderate
- WA:
- High
- MT:
- Low
- ND:
- None
- MN:
- Moderate
- WI:
- Low
- MI:
- Moderate
- NY:
- Moderate
- MA:
- Moderate
- OR:
- High
- ID:
- Low
- WY:
- None
- SD:
- None
- IA:
- Low
- IL:
- Low
- IN:
- Low
- OH:
- Low
- PA:
- Low
- NJ:
- None
- CT:
- None
- RI:
- None
- CA:
- Moderate
- NV:
- None
- UT:
- None
- CO:
- None
- NE:
- None
- MO:
- None
- KY:
- None
- WV:
- Low
- VA:
- Low
- MD:
- None
- DE:
- None
- AZ:
- None
- NM:
- None
- KS:
- None
- AR:
- None
- TN:
- None
- NC:
- Low
- SC:
- None
- OK:
- None
- LA:
- None
- MS:
- None
- AL:
- None
- GA:
- None
- TX:
- None
- FL:
- None
- AK:
- None
- HI:
- None
What Hazelnut Pollen Cross-Reacts With
Patients sensitized to one allergen often react to others sharing similar proteins. This map shows the documented molecular overlaps.
Hazel pollen Cor a 1 shares ~67% sequence identity with birch Bet v 1, placing it firmly within the birch-homologous PR-10 Fagales family. Sensitization to hazel pollen frequently co-occurs with birch sensitization, and the OAS food spectrum is essentially the same — dominated by the PR-10 isoform Cor a 1.04 in the hazelnut kernel.
Same PR-10 cross-reactivity as white birch; birch SCIT cross-protects against hazel season
PR-10 kernel isoform — heat-labile OAS; distinct from anaphylactic Cor a 8/9/14
Mal d 1 — canonical Bet v 1 PR-10 OAS food; heat-labile
Pru p 1 PR-10 OAS; typically tolerated cooked; see white-birch for full food table
Hazelnut Kernel Cor a 1.04 — PR-10 Oral Allergy Syndrome (NOT the same as anaphylactic hazelnut allergy)
The hazelnut kernel Cor a 1.04 isoform is a PR-10 protein that cross-reacts with birch Bet v 1 — producing classic OAS (lip tingling, mouth itch, throat itch after raw hazelnut) that resolves immediately when the hazelnut is roasted. This is NOT the same as anaphylactic hazelnut allergy driven by heat-stable storage proteins Cor a 8 (nsLTP), Cor a 9 (11S legumin), or Cor a 14 (2S albumin) — which can cause systemic reactions with cooked forms and require epinephrine carry. Hazel pollen SCIT may reduce Cor a 1.04 OAS but does not address Cor a 8/9/14 anaphylaxis risk. Component-resolved testing is essential to identify which mechanism applies to you.
Is SCIT Right for Your Hazelnut Pollen Allergy?
Answer five questions to assess whether hazel pollen SCIT is appropriate for your allergy profile — keeping in mind that SCIT addresses the inhalant pollen (Cor a 1.01) and PR-10 food OAS, not the anaphylactic kernel food allergy.
How severe are your late-winter respiratory symptoms (January–March) when hazel catkins are releasing pollen?
The Hazelnut Pollen SCIT Protocol
Hazel pollen SCIT uses non-standardized Corylus extract in the same conventional ladder as other Betulaceae. Given hazel's late-winter season, build-up should ideally begin in summer or early fall. A critical pre-treatment step is component-resolved testing to confirm that the patient's allergy is pollen-driven (Cor a 1.01) rather than kernel storage-protein-driven (Cor a 8/9/14), which SCIT does not address.
Injections begin at 1:100,000 w/v and increase incrementally. Patients with active hazelnut kernel OAS (Cor a 1.04 PR-10) may experience transient worsening of hazelnut OAS symptoms during build-up — this resolves at maintenance and does not indicate treatment failure. Ensure 30-minute post-injection observation at all visits. Patients with confirmed Cor a 8/9/14 storage-protein kernel food allergy should continue strict kernel avoidance and carry an epinephrine auto-injector throughout SCIT, as pollen SCIT does not desensitize the kernel food allergy.
Ongoing maintenance sustains Cor a 1 (pollen PR-10) tolerance. Cross-protection against the broader Fagales PR-10 family is expected given the 67% sequence identity between Cor a 1 and Bet v 1. The Itulazax TT-04 family-level evidence confirms the birch-homologous treatment unit includes hazel-season cross-protection.
Lasting benefit (7–12+ years) is expected with full course completion. Quitting before 3 years is associated with higher relapse rates in Fagales SCIT broadly.
Extract Concentration Ladder
You progress through each vial during build-up. Concentration increases ~10x per step.
What the Research Shows for Hazelnut Pollen SCIT
No hazel-pollen-specific SCIT RCT has been conducted. All clinical use extrapolates from the birch-homologous Fagales evidence — the strongest basis being the Itulazax TT-04 Phase 3 trial (634 adults), which documented symptom reduction across the birch-homologous tree season including hazel-season cross-protection as a secondary endpoint.
- Symptom-medication score reduction (birch-homologous season including hazel)65%ALK Itulazax TT-04 Phase 3, EMA 2019, N=634 adults (birch-homologous family-level evidence)
- PR-10 OAS food reaction improvement with birch SCIT55%Bodtger U et al., Allergy 2002; Arvidsson MB et al., Allergy 2002 (conventional SCIT, PR-10 OAS secondary outcomes)
No hazel-pollen-specific SCIT RCT exists. Family-level evidence from Itulazax TT-04 and the Polak 2023 T-cell cross-reactivity data (Allergy 2023) provide the best available support for hazel SCIT within a birch-anchored Fagales approach. Clinicians and patients should understand that hazel pollen SCIT addresses the inhalant Cor a 1.01 allergen and may reduce Cor a 1.04 PR-10 OAS; it does not treat and cannot be expected to reduce reactions driven by heat-stable Cor a 8, Cor a 9, or Cor a 14 kernel storage proteins.
Ready to skip the surprise bills?
At-home allergy shots (SCIT) are designed by board-certified allergists. See the listed SCIT plan rate in our pricing record and request a quote for eligibility, initiation and total care costs.
- MD-ledBoard-certified allergists
- QuoteTotal care estimate
- 50K+Patients treated
- HSA/FSAEligible
Hazelnut Pollen SCIT Side Effects
Hazel pollen SCIT side effects follow the standard inhalant SCIT profile. Patients with active hazelnut kernel OAS via Cor a 1.04 should be counseled that transient worsening of OAS reactions to raw hazelnut may occur during the build-up phase — this is expected and resolves at maintenance.
Local reactions
4 documented| Reaction | Rate | Severity |
|---|---|---|
Injection-site swelling Expected during build-up; resolves within 24 hours | Rate 30–50% | Mild |
Injection-site itching Ice and pre-treatment antihistamine commonly recommended | Rate 20–40% | Mild |
Large local reaction (>25 mm) More frequent in patients with active PR-10 OAS; does not predict systemic risk | Rate 5–10% | Moderate |
Persistent redness and warmth Resolves within 24 hours in most cases | Rate 10–20% | Mild |
Systemic reactions
4 documented| Reaction | Rate | Severity |
|---|---|---|
Rhinitis/conjunctivitis flare Sneezing or watery eyes within minutes to 1 hour; antihistamine responsive | Rate 0.5–1% | Mild |
Urticaria Generalized hives; managed with antihistamines ± epinephrine | Rate 0.1–0.5% | Moderate |
Bronchospasm Asthmatic patients at higher risk; spirometry before starting SCIT is recommended | Rate 0.1–0.3% | Moderate |
Anaphylaxis Rare at properly titrated doses; Curex supervises the first injection from each new vial or concentration live in the Virtual Shot Room and confirms a prescribed epinephrine auto-injector on hand | Rate <0.01% | Severe |
IMPORTANT: Patients with confirmed hazelnut kernel food allergy driven by Cor a 8, Cor a 9, or Cor a 14 storage proteins should NOT assume that hazel pollen SCIT will desensitize their kernel food allergy. These patients must continue strict kernel avoidance and carry an epinephrine auto-injector throughout and after SCIT. The 30-minute post-injection observation period applies to all hazel SCIT visits.
SCIT vs Alternatives for Hazelnut Pollen
Hazel-pollen-allergic patients have four main options: Fagales-anchored SCIT (covering hazel via birch-homologous cross-protection), at-home sublingual drops, avoidance (limited given hazel's urban and PNW-ubiquitous distribution), and daily medications during the winter pollen window.
| Criterion | At-Home SCIT (Curex)Best | SLIT | Avoidance | Medications |
|---|---|---|---|---|
| Effectiveness | High — family-level Phase 3 evidence (Itulazax TT-04 covers hazel season as secondary endpoint) | Moderate — no FDA-approved hazel SLIT tablet; off-label drops available | Low — hazel pollen is widely distributed in PNW and Northeast | Moderate — antihistamines + nasal steroids for mild-to-moderate symptoms |
| 5-yr cost | $3,500–$15,000 over 5 years | Off-label drops (varies by pharmacy; no FDA-approved hazel tablet) | Low — HEPA, pollen masks, windows closed | $500–$2,000 over 5 years |
| Duration | 3–5 year course | 3–5 year course | Indefinite — no tolerance change | Indefinite — seasonal use every year |
| Convenience | At-home self-injection; weekly build-up 3–6 months, best initiated in summer | Daily at-home — no clinic required | Moderate inconvenience January–March | High convenience |
| Safety | Excellent; Virtual Shot Room–supervised dosing + prescribed epi | Favorable — no systemic anaphylaxis in EU SLIT trials | Safe | Generally safe |
| Lasting effect | 7–12+ years after completion | Emerging data — less durability evidence than SCIT | None — symptoms return each late winter | None — must use every season |
At-Home SCIT (Curex)Best
SLIT
Avoidance
Medications
SCIT anchored to the birch-homologous Fagales family is a highly effective lasting option for hazel pollen allergy — providing cross-season protection against hazel, alder, birch, and oak in one treatment course, with the strongest durability evidence of the immunotherapy routes (sublingual drops remain a valid alternative). Curex now delivers that SCIT as an at-home allergy shot with pricing confirmed in a current program quote: a Fagales PR-10 serum compounded under USP <797>, with the first injection from each new vial or concentration supervised live in the Virtual Shot Room, a prescribed epinephrine auto-injector confirmed on hand, and allergist-overseen escalation — so hazel-sensitized patients get the cross-season protection without weekly clinic trips.
What Hazelnut Pollen SCIT Actually Costs
Hazel pollen SCIT is covered by most major US insurers under standard allergy immunotherapy benefits when prescribed by a board-certified allergist with a positive skin test or specific IgE result for hazel pollen. Hazel is typically included as part of a Fagales mix rather than a standalone extract — pre-authorization should specify the full tree mix composition. Curex at-home IgE testing identifies specific hazelnut pollen sensitization before allergist consultations, eliminating the need for an initial skin-test visit.
Cost range varies by deductible, co-insurance, and clinic.
Verify these codes with your insurer to confirm coverage.
See the listed Environmental Allergy Shots Plan rate, commercial terms dated 2026-10-12; consultations are included without copay. Confirm availability, eligibility, other included services, testing, any in-person care, insurance responsibility and billing cadence in your written quote before enrolling.
Join the waitlistStop guessing about your hazelnut pollen allergy. Get a plan.
Take Curex’s 3-minute allergy quiz. A board-certified allergist will review your symptoms and recommend the right immunotherapy path for you — shots or drops.
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Hazelnut Pollen SCIT — Frequently Asked
Quick answers to the questions patients ask most before starting treatment.
It depends on which type of hazelnut allergy you have. There are three distinct hazelnut allergy mechanisms. First, Cor a 1.01 is the pollen isoform — an inhalant allergen and the target of hazel pollen SCIT. Second, Cor a 1.04 is a kernel isoform that cross-reacts with Bet v 1 (birch) via shared PR-10 structure, producing heat-labile oral allergy syndrome (tingling when eating raw hazelnut, resolved by roasting). Hazel pollen SCIT may reduce this PR-10 OAS over time. Third, Cor a 8, Cor a 9, and Cor a 14 are kernel storage proteins — heat-stable, potentially anaphylactic, and entirely unrelated to the pollen. Hazel pollen SCIT does NOT treat Cor a 8/9/14-driven food allergy. A component-resolved allergy test is the only way to determine which mechanism applies to you — and this distinction determines whether SCIT is appropriate and whether you need an epinephrine auto-injector.
Cor a 1.01 is the pollen isoform of the hazel Cor a 1 allergen — the protein that sensitizes you through inhalation during hazel catkin season. It is the target of hazel pollen SCIT. Cor a 1.04 is the kernel (nut) isoform — a protein found in raw hazelnut that cross-reacts with birch Bet v 1 via shared PR-10 structure, causing oral allergy syndrome when birch-sensitized patients eat raw hazelnuts. Cor a 1.04 is heat-labile (destroyed by cooking or roasting), which is why roasted hazelnut is usually tolerated by PR-10 OAS patients. Both are considered Cor a 1 allergens, but they are structurally distinct isoforms with different clinical implications. Neither is the same as the anaphylactic storage proteins Cor a 9 or Cor a 14.
Hazel (Corylus avellana and C. americana) is one of the earliest-flowering deciduous trees in temperate North America, second only to red alder in the Pacific Northwest. Catkin development begins in autumn and pollen is released as soon as temperatures rise above 5°C — which can happen as early as mid-January in mild PNW winters or in protected southern exposures. In the Northeast, hazel typically peaks in February–March. This very early pollen release is often the cause of 'pre-spring' allergies that patients — and sometimes clinicians — don't immediately attribute to a tree pollen.
They overlap significantly but are not identical. Cor a 1 (hazel) and Bet v 1 (birch) share ~67% amino-acid identity, meaning patients sensitized to one often test positive to the other via cross-reactivity. In practice, most 'hazel-allergic' patients in the northeastern US are birch-primary sensitized with downstream hazel cross-reactivity. However, in the PNW where hazel pollinates before birch, some patients may be hazel-primary sensitized. The clinical importance of this distinction is that a birch-anchored Fagales SCIT mix should cross-protect against hazel season in most patients — but if hazel is a primary sensitizer, adding hazel extract explicitly to the mix may provide better coverage.
Yes, through the birch-homologous PR-10 cross-protection mechanism. Because Cor a 1 shares the same PR-10 structural fold as Aln g 1 (alder, 88% Bet v 1 identity), Que a 1 (oak, 72–95% identity), and Fag s 1 (beech, 66% identity), a Fagales-anchored SCIT extract — whether anchored to birch or hazel — typically provides cross-season protection across the entire Fagales tree group. The Itulazax TT-04 trial confirmed this cross-season effect explicitly in birch-sensitized patients for the alder, hazel, and oak seasons as secondary endpoints. Your allergist will determine the most appropriate Fagales mix for your specific region.
Most patients notice improvement during the hazel season after completing 6–12 months of build-up injections. Because hazel season is compressed into 4–8 late-winter weeks, it may take two full seasons to accurately assess benefit. The earliest hazel seasons tend to be the clearest read — if you can clearly feel improved from year 1 to year 2, that's a strong signal SCIT is working. Full immunologic tolerance develops over 3–5 years, and completing the full course is associated with lasting benefit for 7–12 years after stopping. Dropping out at year 1 is associated with rapid return of symptoms.
Yes, antihistamines are generally compatible with hazel SCIT. Many allergists recommend taking a non-sedating antihistamine (such as cetirizine or loratadine) on injection days to reduce local swelling at the injection site. However, antihistamines can mask early signs of systemic reactions — so you should always inform the clinic about any current medications before each injection visit. Do not take antihistamines specifically to hide systemic symptoms so you can proceed with an injection without informing the nurse — this is unsafe. Continue taking nasal corticosteroids as directed throughout the SCIT course; they do not interfere with treatment.
This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about a medical condition. Content reviewed by board-certified allergists at Curex.
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