Nasal allergies: causes, symptoms, and treatment

What are nasal allergies?

Nasal allergies (allergic rhinitis) occur when the immune system mistakenly identifies normally harmless environmental particles as threats. These allergens can include pollen, dust mites, pet dander, mold spores, and cockroach droppings. Upon exposure, the immune system produces specific antibodies, immunoglobulin E (IgE), against the allergen.

Re-exposure triggers these IgE antibodies to activate mast cells, causing the release of histamine and other chemical mediators. This histamine release leads to inflammation of the nasal passages, causing blood vessels to swell, increased mucus production, and nerve irritation – resulting in classic allergy symptoms such as sneezing, nasal congestion, runny nose, and itching (nasal pruritis).

Allergic rhinitis is different from viral infections like the common cold, which resolve after a short period, whereas allergies persist as long as allergen exposure continues. In addition to immediate early-phase reactions caused by histamine, a late-phase allergic response involves cytokine release (e.g., interleukins IL-4 and IL-13), further recruiting inflammatory cells like eosinophils, leading to prolonged nasal mucosal inflammation and hyperresponsiveness. Chronic nasal allergy can make the nasal lining overly sensitive to non-allergic stimuli such as smoke or cold air.

Common causes of nasal allergies

The principal allergens fall into two broad categories:

• Seasonal allergens: Pollen from trees, grasses, and weeds, causing symptoms primarily during specific seasons like spring, summer, or fall, collectively known as hay fever.
• Perennial allergens: Those present year-round, such as dust mites in bedding and carpets, pet dander from cats and dogs, mold spores in damp environments, and cockroach droppings.

Environmental irritants like cigarette smoke, pollution, strong odors, and chemical fumes do not directly cause allergies but can worsen symptoms, particularly in sensitive individuals. Changes in temperature, humidity, or exposure to air conditioning can also exacerbate symptoms.

Air pollution, particularly traffic-related pollutants (nitrogen dioxide, sulfur dioxide, particulate matter), has been shown to increase the prevalence and severity of allergic rhinitis by impairing nasal respiratory barriers, promoting inflammation, and enhancing allergic responses. Diesel exhaust particles amplify eosinophil activation in the presence of allergens, intensifying symptoms. Urbanization and environmental degradation have contributed to the global rise in nasal allergy cases.

How the body react?

Upon allergen exposure, immune cells produce allergen-specific IgE antibodies. When allergens bind these IgE antibodies on mast cells in the nasal mucosa, it leads to mast cell activation and degranulation. Histamine, a key mediator released, stimulates nerve endings causing sneezing, stimulates mucous glands producing runny nose, and causes blood vessel dilation resulting in congestion.

Beyond histamine, other mediators like leukotrienes and prostaglandins play roles in swelling and mucus production. The late-phase immune response recruits inflammatory cells, worsening symptoms and causing persistent nasal tissue swelling and hyperreactivity to non-allergic triggers. This process underlies chronic nasal symptoms in allergic rhinitis.

Typical symptoms of nasal allergies

Common symptoms coughing and sneezing allergies include:

• Frequent sneezing and a runny nose with clear mucus
• Nasal congestion and stuffiness
• Itchy nose, eyes, throat, and ears
• Watery, red eyes often accompanied by puffiness
• Postnasal drip leading to throat clearing and coughing
• Fatigue and disrupted sleep due to nasal blockage or daytime discomfort

Immediate remedies to relieve symptoms

Initial management of nasal allergies focuses on symptom control. Options include:

• Over-the-counter antihistamines: These block histamine receptors, reducing sneezing, itching, and runny nose. Non-sedating antihistamines are preferred though some may cause drowsiness.
• Decongestants: Oral or nasal sprays constrict blood vessels to relieve nasal swelling and congestion. Nasal decongestant sprays should be limited to a few days to avoid rebound congestion.
• Nasal corticosteroid sprays: First-line for long-term control, they reduce local inflammation. Effects may take several days and require proper administration technique to avoid side effects like nasal irritation or nosebleeds.
• Saline nasal irrigation: Rinsing nasal passages with saline solutions helps flush out allergens and mucus, offering drug-free relief and improving symptoms.
• Home care: Staying hydrated to thin mucus and avoiding known allergens are practical steps that support symptom management.

Lifestyle changes and environmental controls

To minimize symptoms, individuals can take practical steps at home and outdoors:

• Keep windows and doors closed during high pollen seasons to prevent allergens from entering.
• Use air purifiers with HEPA filters to remove airborne allergens inside.
• Maintain indoor humidity between 30 – 50% to limit dust mite and mold growth.
• Frequently clean bedding, carpets, and curtains in hot water to remove dust mites and dander.
• Use allergen-proof mattress and pillow covers.
• Vacuum regularly with a HEPA-filter vacuum cleaner.
• Keep pets out of bedrooms and off furniture if allergic to pet dander.
• Avoid outdoor activities early in the morning or on windy days when pollen counts peak
• Wear sunglasses and masks outdoors to reduce allergen contact.

Long-term treatment options

For persistent or severe allergic rhinitis, more comprehensive treatment can offer better control:

• Allergy immunotherapy: Allergy shots (subcutaneous) or tablets (sublingual) gradually desensitize the immune system to specific allergens by exposing it to increasing doses over months or years. This can result in long-lasting symptom reduction and decreased medication use. Immunotherapy may prevent new allergies and the progression of allergic diseases such as asthma.
• Prescription medications: For severe symptoms, stronger antihistamines, corticosteroids, or leukotriene receptor antagonists may be prescribed.
• Managing related conditions: Since nasal allergies often coexist with asthma or sinus infections, integrated treatment plans may be needed.

When to see a doctor?

It is important to seek medical advice if:

• Symptoms do not improve with standard treatments.
• Nasal congestion persists leading to breathing difficulties or frequent sinus infections.
• There are signs of severe allergic reactions, such as swelling of the face or difficulty breathing.
• Allergies affect sleep, daily activities, or work performance significantly.
• One needs personalized treatment plans including immunotherapy or prescription medications.

Conclusion

Nasal allergies, though common and sometimes persistent, can be effectively managed with a comprehensive understanding of their causes and available treatments. Recognizing triggers, applying environmental controls, employing suitable medications, and seeking specialist care when needed can significantly enhance symptom control and quality of life. Adopting these proactive measures allows individuals to breathe easier and enjoy life without the interruptions nasal allergies often cause.