```html

Hay Fever (Allergic Rhinitis)

Overview

Hay fever, medically termed allergic rhinitis, is an inflammation of the nasal lining caused by an immune response to airborne allergens such as pollen, dust‑mite particles, animal dander, or mold spores. The condition is non‑infectious, meaning it does not spread from person to person.

It affects people of all ages, but prevalence peaks in school‑age children and young adults. According to the U.S. Centers for Disease Control and Prevention (CDC), about 20 % of the U.S. population (≈ 60 million people) experiences some form of allergic rhinitis each year. Worldwide, the World Health Organization estimates that up to 30 % of the global population suffers from allergic airway disease, making it one of the most common chronic allergic conditions.

Symptoms

Symptoms result from the release of histamine and other inflammatory mediators when the immune system mistakenly identifies harmless particles as threats. They can be intermittent (seasonal) or persistent (perennial).

• Sneezing – sudden, repetitive bursts, often triggered by exposure to the allergen.
• Runny nose (rhinorrhea) – clear, watery discharge that may become thick if infection develops.
• Nasal congestion – feeling of blocked nose, swelling of nasal turbinates.
• Itchy nose, palate, or throat – a tingling sensation that can cause frequent throat clearing.
• Watery, itchy eyes (allergic conjunctivitis) – redness, swelling, and tearing.
• Post‑nasal drip – mucus drips down the back of the throat, leading to cough or sore throat.
• Fatigue – disrupted sleep from congestion or nighttime coughing.
• Headache – especially frontal pain from sinus pressure.
• Ear fullness or popping – due to eustachian tube dysfunction.

Symptoms usually appear within minutes of contact with the allergen and may persist for hours to days, depending on exposure intensity.

Causes and Risk Factors

Immunologic cause

The underlying mechanism is a type I hypersensitivity reaction. When a sensitized individual inhales an allergen, B‑cells produce Immunoglobulin E (IgE) antibodies that bind to mast cells in the nasal mucosa. Subsequent exposures trigger mast‑cell degranulation, releasing histamine, leukotrienes, and prostaglandins—substances that cause the classic allergic symptoms.

Common allergens

• Pollen – tree (spring), grass (late spring/early summer), ragweed (late summer/fall).
• Dust mites – microscopic organisms that thrive in warm, humid bedding and upholstery.
• Animal dander – proteins found in skin flakes, saliva, and urine of cats, dogs, rodents.
• Mold spores – indoor (e.g., Cladosporium) and outdoor (e.g., Alternaria) varieties.
• Cockroach debris – especially relevant in densely populated urban housing.

Risk factors

• Family history of atopy (asthma, eczema, allergic rhinitis).
• Living in environments with high allergen loads (e.g., homes with carpets, pets, or poor ventilation).
• Exposure to tobacco smoke or air pollution, which can enhance airway inflammation.
• Occupational exposure to chemicals or dust (e.g., farmers, textile workers).
• Age: childhood onset is common, but new sensitization can occur at any age.

Diagnosis

Diagnosis is primarily clinical, based on symptom pattern and trigger exposure. A thorough history and physical examination are essential.

Key steps

1. Medical history – onset, seasonality, symptom severity, known allergens, family history, and impact on daily life.
2. Physical exam – inspection of nasal mucosa (pale, boggy tissue), eye conjunctiva (redness), and throat.
3. Allergy testing (if the trigger is unclear):
   • Skin prick test (SPT) – small amounts of standardized allergen extracts are introduced into the skin; a raised wheal within 15–20 minutes indicates sensitization.
   • Serum-specific IgE test (e.g., ImmunoCAP) – measures circulating IgE antibodies to specific allergens.
4. Nasal endoscopy – occasionally used to rule out structural issues (e.g., polyps, deviated septum).
5. Imaging – rarely needed, but a sinus CT may be ordered if chronic sinusitis is suspected.

According to the Mayo Clinic, a positive allergy test combined with consistent symptoms confirms allergic rhinitis.

Treatment Options

Treatment is individualized, aiming to reduce symptoms, improve quality of life, and prevent complications. Options fall into three broad categories: medication, allergen‑specific interventions, and lifestyle modifications.

Medications

• Intranasal corticosteroids (INS) – first‑line for moderate‑to‑severe disease (e.g., fluticasone, mometasone). They reduce inflammation and are safe for long‑term use.<sup>1</sup>
• Antihistamines – oral second‑generation agents (cetirizine, loratadine, fexofenadine) are non‑sedating; topical antihistamine sprays (azelastine) work quickly.
• Decongestants – oral (pseudoephedrine) or intranasal (oxymetazoline) for short‑term relief; avoid >3‑5 days of nasal spray to prevent rebound congestion.
• Lavage (saline irrigation) – isotonic or hypertonic saline rinses help clear mucus and allergens.
• Leukotriene receptor antagonists (LTRAs) – montelukast can be useful, especially in patients with concomitant asthma.
• Biologic therapy – for severe, refractory cases, monoclonal antibodies such as dupilumab (IL‑4Rα antagonist) have shown efficacy (FDA approved 2022).<sup>2</sup>

Allergen‑specific interventions

• Allergen avoidance – the cornerstone; see Prevention section.
• Allergy immunotherapy:
  • Subcutaneous immunotherapy (SCIT) – weekly injections of gradually increasing allergen doses over 3–5 years.
  • Sublingual immunotherapy (SLIT) – daily tablets or drops placed under the tongue; increasingly preferred for dust‑mite and grass pollen allergies.
  Both modalities can modify the disease course, reducing the need for medications.

Lifestyle & environmental measures

• Use of HEPA air filters.
• Regular washing of bedding in hot water (≥ 130 °F/54 °C) to eradicate dust mites.
• Keeping windows closed during high pollen counts; using air conditioning.
• Showering and changing clothes after outdoor activities.

Living with Hay Fever (Allergic Rhinitis)

Effective day‑to‑day management can dramatically reduce symptom burden.

• Track triggers – keep a simple diary of symptoms, pollen counts (available from local weather services), and indoor conditions.
• Medication schedule – take daily INS in the morning; antihistamines can be taken as needed, but consistent dosing improves control.
• Nasal spray technique – tilt head forward, aim nozzle toward the outer side of the nostril, sniff gently, and avoid blowing the nose for 10 minutes.
• Humidify appropriately – maintain indoor humidity between 30‑50 % (too dry irritates mucosa; too humid encourages mold).
• Exercise safely – indoor workouts on low‑allergen days; wear a mask outdoors when pollen is high.
• Sleep hygiene – elevate the head of the bed or use a nasal strip to reduce congestion at night.

Prevention

While you cannot eliminate genetic predisposition, you can dramatically lower exposure and sensitization risk.

1. Environmental control
   • Use allergen‑proof encasements on mattresses and pillows.
   • Vacuum with a HEPA filter at least twice weekly.
   • Remove carpets or rugs in bedrooms.
   • Keep pets out of the bedroom; bathe them weekly.
2. Seasonal actions
   • Check daily pollen forecasts; limit outdoor activities when counts exceed 50 grains/m³.
   • Wear sunglasses outdoors to reduce eye exposure.
   • Rinse face and hair after returning indoors.
3. Medical prevention
   • Start intranasal corticosteroids before the pollen season (e.g., 2–4 weeks early) to pre‑empt inflammation.
   • Consider pre‑seasonal antihistamine therapy for known pollen allergies.

Complications

If left untreated or poorly controlled, allergic rhinitis can lead to several secondary problems:

• Sinusitis – chronic inflammation can block sinus drainage, causing bacterial infection.
• Otitis media – eustachian tube dysfunction may lead to middle‑ear infections, especially in children.
• Sleep disturbances – snoring, obstructive sleep apnea, or frequent night awakenings.
• Asthma exacerbation – upper‑airway inflammation can worsen lower‑airway disease; up to 40 % of asthmatic patients have concurrent allergic rhinitis (per NIH).
• Reduced quality of life – poor concentration, decreased work or school performance, and emotional distress.

When to Seek Emergency Care

---

References:

1. Mayo Clinic. Allergic rhinitis – Diagnosis and treatment. https://www.mayoclinic.org/…. Accessed April 2026.
2. U.S. Food & Drug Administration. Dupilumab (Dupixent) FDA label. https://www.fda.gov/…. Accessed April 2026.
3. National Institute of Allergy and Infectious Diseases. Allergic Rhinitis. https://www.niaid.nih.gov/…. Accessed April 2026.
4. World Health Organization. Global report on allergy. 2023. https://www.who.int/…. Accessed April 2026.
5. Cleveland Clinic. Allergic rhinitis treatment options. https://my.clevelandclinic.org/…. Accessed April 2026.

```