Crepe Myrtle Allergy Shots: Why Late-Summer Symptoms Are Ragweed
Crepe myrtle (Lagerstroemia indica) is bee and butterfly-pollinated with heavy, sticky pollen not aerosolized in clinical concentrations — no IUIS-named allergen, no published sensitization study, and SCIT is not routinely indicated. The dramatic July–September bloom directly overlaps short-ragweed and bahiagrass season, making crepe myrtle the 'late-summer visual scapegoat' for symptoms driven by true wind-borne aeroallergens.
Crepe Myrtle Allergy Immunotherapy: How It Works
Allergy immunotherapy is the only long-term treatment that re-trains the immune system to stop overreacting to crepe myrtle — rather than just masking symptoms with antihistamines or steroids. By gradually exposing the body to controlled doses of crepe myrtle 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 crepe myrtle 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 crepe myrtle 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 crepe myrtle 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
Allergy Drops / Tablets (SLIT)
Daily drops or dissolvable tablets containing crepe myrtle 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 crepe myrtle 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 crepe myrtle allergy with at-home drops, see how Curex sublingual immunotherapy compares below.
What is Crepe Myrtle?
The biology, taxonomy, and clinical fingerprint of Crepe Myrtle — the foundation of how SCIT targets it.
Crepe myrtle (Lagerstroemia indica) in dramatic late-summer bloom — bee-pollinated, not wind-dispersed. Symptoms during July–September bloom period almost always reflect concurrent ragweed or warm-season grass pollen, not crepe myrtle.
- Scientific name
- Lagerstroemia indica
- Family
- LythraceaeLoosestrife family
- Type
- Insect-pollinated (bee, butterfly) ornamental deciduous tree
- Native to
- China and the Indian subcontinent; widely planted ornamental across the southern US
- Allergen proteins
- No IUIS-named Lagerstroemia pollen allergen as of May 2026
- Particle size
- Heavy, sticky — not aerosolized in clinical concentrations
- Avoidance difficulty
- Easy
How Crepe Myrtle Allergy Presents
Symptoms by body system — useful for distinguishing Crepe Myrtle sensitivity from overlapping allergies and infections.
Respiratory (likely ragweed or grass — not crepe myrtle)
- Late-summer rhinitis and sneezing (July–September) in the South are caused by short-ragweed, bahiagrass, and johnson-grass — not crepe myrtle pollen
- Crepe myrtle's bee-pollinated flowers produce pollen that does not become airborne in clinical concentrations
- Respiratory symptoms near crepe myrtles in bloom reflect the same ragweed season that coincides with the visual bloom display
Ocular (likely ragweed — not crepe myrtle)
- Allergic conjunctivitis during July–September reflects short-ragweed pollen season, not crepe myrtle
- Ragweed is responsible for approximately 75% of late-summer allergic rhinoconjunctivitis in the eastern and southern US
Dermal
- Contact dermatitis from crepe myrtle sap reported in landscape workers — not IgE-mediated pollen allergy
- Powdery mildew (Erysiphe lagerstroemiae) on infected crepe myrtle leaves releases fungal spores that can act as airborne allergens — a SEPARATE allergen pathway from the pollen
- No documented OAS food cross-reactivity for Lagerstroemia pollen
Systemic
- Systemic fatigue and malaise during late summer reflect the ragweed and grass pollen burden, not crepe myrtle
- Fungal spores from powdery mildew on infected crepe myrtle represent a secondary airborne exposure — patients with mold allergy may react to this separately from pollen
- No published case reports of anaphylaxis attributable to Lagerstroemia pollen
Crepe myrtle blooms when ragweed peaks across the South — patients blame the dramatic pink tree, but the testing always lands on ragweed or bahiagrass. The crepe myrtle's visual dominance in the southern landscape is inversely proportional to its clinical significance as an aeroallergen.
When & Where Crepe Myrtle Peaks
Allergen intensity by month and by state. Useful for timing SCIT start dates and travel planning.
12-Month Intensity
Crepe myrtle bloom: July–September. Pollen is not airborne. Late-summer symptoms coincide with peak short-ragweed and bahiagrass season.· Bee-pollinated — no aeroallergen season. Bloom directly overlaps short-ragweed (August–October) and warm-season grass seasons across the southern US.
US Exposure Map
0 high-intensity statesWhat Crepe Myrtle Cross-Reacts With
Patients sensitized to one allergen often react to others sharing similar proteins. This map shows the documented molecular overlaps.
Crepe myrtle pollen has no documented IgE cross-reactivity; the critical 'cross-exposure' for patients is the co-occurring short-ragweed and bahiagrass season that begins in July–September.
Is SCIT Right for Your Crepe Myrtle Allergy?
If you suspect crepe myrtle is causing your late-summer allergies, these questions redirect the diagnostic workup toward the true likely aeroallergens.
Do your worst allergy symptoms peak in August–October?
The Crepe Myrtle SCIT Protocol
SCIT is not routinely indicated for crepe myrtle (Lagerstroemia indica) — the pollen is bee-pollinated and not airborne, no IUIS-named allergen exists, and no trial supports crepe-myrtle-specific immunotherapy. Curex IgE testing distinguishes late-summer symptoms attributed to crepe myrtle from the true culprits — typically ragweed or warm-season grasses — before any treatment plan is designed.
SCIT build-up for crepe myrtle pollen is not clinically indicated. SCIT build-up for confirmed co-occurring late-summer aeroallergens (ragweed, bahiagrass) follows the standard schedule and should begin in winter or early spring to reach maintenance before the August–October peak.
SCIT maintenance for crepe myrtle is not supported by evidence. Maintenance for ragweed SCIT uses FDA-standardized short-ragweed extract, which is the highest-evidence target for late-summer Southern allergy.
Not applicable for crepe-myrtle-specific SCIT.
Extract Concentration Ladder
You progress through each vial during build-up. Concentration increases ~10x per step.
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Crepe Myrtle SCIT Side Effects
SCIT is not indicated for crepe myrtle. The side-effect profile of ragweed and bahiagrass SCIT — the appropriate treatments for late-summer southern allergy — applies here.
Local reactions
2 documentedSystemic reactions
2 documentedCurex delivers SCIT for confirmed late-summer aeroallergens (ragweed, bahiagrass) as an at-home allergy shot: a prescribed epinephrine auto-injector is confirmed on hand and the first dose plus every dose change are supervised live over Zoom by a board-certified allergist. Crepe-myrtle-specific SCIT is not indicated.
SCIT vs Alternatives for Crepe Myrtle
The most effective alternative for late-summer southern allergy attributed to crepe myrtle is correct diagnosis — testing for and treating short-ragweed and bahiagrass, which share the July–September bloom window.
| Criterion | At-Home SCIT (Curex) · ragweed/bahiagrassBest | SLIT Drops | Avoidance | Medications |
|---|---|---|---|---|
| Effectiveness | Strong (RCT-proven for ragweed) | Moderate (extrapolated) | Moderate (wind-borne pollen hard to avoid) | Good symptom control |
| 5-yr cost | $3,500–$15,000 | $1,500–$4,000 | $0–$300/yr | $200–$1,200/yr |
| Duration | 3–5 years | 3–5 years | Indefinite | Indefinite |
| Convenience | At-home self-injection; weekly then monthly | Daily at home | Lifestyle adjustments | Daily for 3–4 months/yr |
| Safety | Zoom-supervised dosing + prescribed epi | Self-administered | No medical risk | Generally safe |
| Lasting effect | 7–12 yrs post-course | Ongoing use needed | No lasting change | No lasting change |
At-Home SCIT (Curex) · ragweed/bahiagrassBest
SLIT Drops
Avoidance
Medications
For patients with late-summer southern allergy attributed to crepe myrtle, accurate diagnosis is the first step. Curex IgE testing identifies the true sensitizers — typically ragweed or warm-season grasses — and our at-home allergy shot at $129/month all-inclusive targets those confirmed ragweed and grass sensitizers that drive the actual July–September allergy burden across the southern US, with a prescribed epinephrine auto-injector confirmed on hand and the first dose supervised live over Zoom by a board-certified allergist.
What Crepe Myrtle SCIT Actually Costs
Insurance covers SCIT for confirmed late-summer aeroallergens (short-ragweed uses FDA-standardized extract; bahiagrass and bermuda grass use standardized grass extracts) when prescribed by a board-certified allergist. Crepe myrtle SCIT lacks the evidence base for insurance authorization. Accurate sensitization testing is the covered diagnostic first step.
Cost range varies by deductible, co-insurance, and clinic.
Verify these codes with your insurer to confirm coverage.
Flat monthly subscription — includes consult, prescription, and at-home dosing for sublingual immunotherapy.
See if you qualifyStop guessing about your crepe myrtle 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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Crepe Myrtle SCIT — Frequently Asked
Quick answers to the questions patients ask most before starting treatment.
Crepe myrtle (Lagerstroemia indica) blooms from July through September across the southern United States — the same period when short-ragweed (Ambrosia artemisiifolia) reaches peak pollen production from late July through October. This calendar coincidence creates a systematic misattribution pattern: the spectacular pink, white, and purple crepe myrtle trees are visually impossible to miss in the southern landscape, while the true culprit (ragweed) is an inconspicuous weed. Ragweed pollen is wind-borne and travels for miles; crepe myrtle pollen is heavy, sticky, and bee-carried. Any late-summer rhinitis symptoms coinciding with crepe myrtle bloom should be evaluated by a board-certified allergist for ragweed and warm-season grass sensitization before attributing them to the ornamental tree.
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.