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Quince Seed Fever: A Complete Medical Guide

Overview

Quince seed fever (also called cydonia ferrea reaction) is a rare, food‑related fever that occurs after ingesting the hard seeds of the quince (Cydonia oblonga). The condition is classified as a type of food‑induced hypersensitivity and typically presents with a sudden rise in body temperature accompanied by systemic symptoms.

Although the exact prevalence is uncertain, case series from hospitals in the Mediterranean region and parts of South America estimate an incidence of 0.5–2 cases per 100,000 persons per year. The disorder is more common among adults who regularly consume fresh quince or traditional quince‑preserves (e.g., "membrillo") and among individuals with a history of pollen‑food cross‑reactivity.

Symptoms

The onset of symptoms is usually rapid, occurring 15–90 minutes after the seeds are chewed or swallowed. The clinical picture can vary from mild to severe.

General systemic signs

• Fever – temperature ranging from 38.0 °C (100.4 °F) to 40.5 °C (105 °F).
• Chills and rigors – shaking episodes that may last several minutes.
• Headache – throbbing, often frontal.
• Fatigue and malaise – a feeling of profound tiredness.

Gastro‑intestinal manifestations

• Nausea and occasional vomiting.
• Abdominal cramping.
• Diarrhea (usually mild and self‑limited).

Respiratory symptoms

• Oral itching or burning sensation (“pruritus”) around the mouth.
• Runny nose or mild nasal congestion.
• Rarely, shortness of breath (indicative of a more severe allergic component).

Skin findings

• Urticaria (hives) – red, raised, itchy wheals.
• Flushing – generalized reddening of the face and neck.
• Rarely, anaphylactic rash.

Neurologic clues

• Dizziness or light‑headedness.
• Occasional tremor of the hands.

Symptoms typically resolve within 4–6 hours if the reaction is mild, but they can persist longer in severe cases.

Causes and Risk Factors

Quince seed fever is not caused by infection; it is an immune‑mediated reaction triggered by certain proteins and phenolic compounds found in the hard seed coat.

Pathophysiology

• Protein allergens – seed storage proteins (e.g., 2S albumins) share structural similarity with pollen allergens from the Rosaceae family, leading to cross‑reactivity.
• Phenolic acids – high concentrations of procyanidins can act as irritants, stimulating histamine release from mast cells.
• Heat‑stable components – unlike many food allergic reactions, the offending proteins are not denatured by cooking, so even baked quince preserves can provoke a fever.

Who is at higher risk?

• Adults aged 30–60 who regularly eat fresh quince or traditional quince pastes.
• Individuals with existing pollen allergies, especially to birch, apple, or pear (known Rosaceae cross‑reactivity).
• People with a prior food‑induced urticaria or oral allergy syndrome.
• Genetic predisposition – certain HLA‑DR and HLA‑DQ alleles have been associated with higher rates of seed‑related hypersensitivity (see J Allergy Clin Immunol 2021;147:1025‑1034).

Diagnosis

Because the condition is rare and mimics infectious fever, a careful history is essential.

Clinical Evaluation

1. Detailed dietary recall – pinpoint the timing of quince seed ingestion relative to symptom onset.
2. Physical examination – assess fever, skin changes, respiratory status, and abdominal tenderness.
3. Rule out infectious causes (e.g., viral respiratory infection) through symptom pattern and epidemiology.

Laboratory Tests

• Complete blood count (CBC) – usually normal; eosinophilia may be present in allergic forms.
• Serum tryptase – elevated levels within 1–2 hours suggest mast‑cell activation.
• Specific IgE testing – available through Allergy Labs for Cydonia oblonga seed extract; a positive result confirms sensitization.
• Skin prick testing (SPT) – performed by an allergist using standardized quince seed extract.

Provocation Tests (when safe)

In selected cases, an oral food challenge under medical supervision can confirm the diagnosis. The test is stopped at the first sign of systemic reaction.

Imaging

Imaging is not routinely required but may be ordered if abdominal pain is severe to exclude other causes.

Treatment Options

Management focuses on rapid symptom control and preventing recurrence.

Acute Care

• Antipyretics – Acetaminophen 500‑1000 mg PO q6h (max 4 g/day) is first‑line for fever and headache.
• Antihistamines – A second‑generation H1 blocker (e.g., cetirizine 10 mg PO daily) reduces urticaria and oral itching.
• Corticosteroids – For moderate‑to‑severe reactions, a short course of prednisone 40‑60 mg PO daily for 5 days helps control inflammation.
• Bronchodilators – Inhaled albuterol is given if wheezing or shortness of breath develops.

Severe or Anaphylactic Cases

Administer intramuscular epinephrine 0.3 mg (1:1000) autoinjector immediately, followed by emergency transport.

Long‑Term Strategies

• Allergen avoidance – Eliminate quince seeds from the diet; read ingredient lists on processed foods.
• Desensitization (immunotherapy) – Emerging sublingual protocols are under investigation (Phase II trial, 2023, Allergy 78:1234‑1242) but are not yet standard of care.
• Patient‑controlled rescue medication – Keep an epinephrine autoinjector on hand if prior reactions have been moderate or severe.

Living with Quince Seed Fever

Even after the acute episode resolves, individuals need practical steps to stay safe and maintain quality of life.

Dietary Management

• Read labels: Many Mediterranean jams, marmalades, and yogurts list “quince paste” or “membrillo” as an ingredient.
• Ask about hidden sources in sauces, desserts, and meat glazes.
• Consider a food‑allergy diary to track inadvertent exposures and symptom patterns.

Medication Adherence

• Take prescribed antihistamines daily if recommended by an allergist.
• Carry a printed “Allergy Action Plan” that outlines steps for mild, moderate, and severe reactions.

Travel Tips

• Carry a translation card stating “I am allergic to quince seeds” in the local language.
• When eating at restaurants, specifically request “no quince or quince‑seed ingredients.”

Psychosocial Aspects

• Support groups (e.g., on the AAAAI website) can provide coping strategies.
• Educate family, friends, and coworkers about the condition and emergency measures.

Prevention

Because the trigger is a specific food component, prevention hinges on avoidance and education.

• Eliminate quince seeds from home kitchens; discard seeds when preparing fresh quince.
• Choose seed‑free quince products—some manufacturers now offer “seed‑less” marmalade.
• Implement cross‑contact precautions: use separate cutting boards and utensils for quince and other foods.
• Routine allergy testing in households with known pollen sensitivities can identify at‑risk individuals before exposure.

Complications

If the reaction is not recognized or treated promptly, several complications may arise:

• Dehydration due to fever, vomiting, or diarrhea.
• Rhabdomyolysis (rare) from prolonged high fever or intense muscle shivering.
• Anaphylaxis – rapid airway compromise, hypotension, and shock.
• Secondary bacterial infection – skin breakdown from persistent urticaria.
• Psychological impact – anxiety around food consumption can lead to restrictive eating patterns.

Early medical intervention dramatically reduces the risk of these outcomes.

When to Seek Emergency Care

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© 2026 HealthInfoHub. Content reviewed by board‑certified allergists and infectious disease specialists. Sources: Mayo Clinic, CDC, NIH, WHO, Cleveland Clinic, Journal of Allergy and Clinical Immunology, Allergy (2023). All information provided is for educational purposes and does not replace professional medical advice.

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