Can weather changes cause a runny nose?

Weather Changes and Runny Nose

Weather changes do not directly cause runny nose through an allergic mechanism, but they significantly influence allergen exposure patterns and can trigger symptoms in individuals with underlying allergic or nonallergic rhinitis through changes in pollen counts, mold spore concentrations, and direct irritant effects on nasal mucosa. 1

Understanding the Mechanism

Weather changes affect runny nose through two distinct pathways:

Allergic Pathway (Indirect Effect)

• Allergic rhinitis is caused by IgE-mediated inflammatory responses to inhaled allergens—not by weather itself. 1 Weather conditions modulate allergen exposure rather than directly causing symptoms.
• Sunny, windy days with low humidity produce the highest pollen counts, triggering symptoms in sensitized individuals. 2
• Gentle sustained rain temporarily reduces airborne pollen, often providing symptom relief. 2
• Temperature and humidity changes dramatically affect fungal spore release: hydrophilic fungi (Fusarium, Phoma) are most abundant during rainy weather, while Alternaria and Cladosporium have elevated levels during dry, windy conditions. 2

Nonallergic Pathway (Direct Effect)

• Cold air exposure directly triggers rhinorrhea, nasal congestion, and nasal burning within minutes through sensory nerve stimulation and cholinergic reflex activation—this is a distinct condition called cold air-induced rhinitis. 3
• Weather/temperature-sensitive vasomotor rhinitis (VMR[w/t]) is triggered by weather and temperature changes through non-IgE mechanisms. 4, 5
• Classic symptoms include nasal congestion, postnasal drip, and sneezing triggered by weather changes, perfumes, and irritant odors. 4

Clinical Differentiation

To determine if weather-related runny nose is allergic or nonallergic, look for these specific features:

Allergic Rhinitis Features

• Nasal itching, sneezing, and ocular symptoms (itching, tearing) are more prominent. 6, 7
• Symptoms correlate with specific seasonal patterns: tree pollen in early-to-mid spring, grasses in late spring/early summer, weeds from late summer until early fall in temperate regions. 1
• Physical examination shows edematous and pale turbinates in seasonal allergic rhinitis; erythematous and inflamed turbinates with serous secretions in perennial allergic rhinitis. 7
• Positive skin prick testing or specific IgE antibodies to aeroallergens. 6, 7

Nonallergic Rhinitis Features

• Nasal congestion and postnasal drainage predominate, with minimal to no itching. 7, 4
• Symptoms triggered by temperature changes, irritant odors, and weather shifts rather than specific allergen exposure. 4
• Negative skin testing for aeroallergens. 7, 4
• Cold air exposure causes immediate rhinorrhea that dissipates soon after exposure terminates. 3

Treatment Approach

For Allergic Rhinitis Triggered by Weather-Related Allergen Changes

• Patients with persistent moderate to severe allergic rhinitis should be treated initially with an intranasal corticosteroid (fluticasone, triamcinolone, budesonide, mometasone) either alone or in combination with an intranasal antihistamine. 7
• Patients with mild intermittent or mild persistent allergic rhinitis may use a second-generation H1 antihistamine (cetirizine, fexofenadine, desloratadine, loratadine) or intranasal antihistamine (azelastine, olopatadine). 7
• Allergen avoidance during high-risk weather conditions: keep windows closed during high pollen counts, limit outdoor activities on sunny, windy days with low humidity. 2

For Weather/Temperature-Sensitive Nonallergic Rhinitis

• First-line therapy consists of an intranasal antihistamine as monotherapy or in combination with an intranasal corticosteroid. 7
• Anticholinergic agents (ipratropium bromide nasal spray) are highly effective for cold air-induced rhinitis because they block the cholinergic reflex that generates rhinorrhea. 3
• Important caveat: Weather/temperature-sensitive vasomotor rhinitis (VMR[w/t]) may be refractory to intranasal corticosteroid treatment alone. 5 A study of fluticasone furoate showed no significant improvement versus placebo in VMR(w/t), suggesting this is a distinct subgroup requiring alternative approaches. 5

Common Pitfalls

• Do not assume all weather-related runny nose is allergic. Many patients have nonallergic rhinitis with eosinophilia or idiopathic nonallergic rhinitis that presents similarly but requires different treatment. 4
• Patients with allergic rhinitis often have symptoms after exposure to irritants and temperature changes, similar to nonallergic rhinitis patients—this is called non-specific nasal hyperreactivity. 6 These patients may need treatment for both conditions.
• Mixed rhinitis (combined allergic and nonallergic) occurs in 44% to 87% of patients with allergic rhinitis and is more common than either pure form. 2 Consider combination therapy addressing both mechanisms.
• Climate change is extending pollen seasons and increasing year-round allergen exposure, fundamentally altering traditional seasonal patterns. 1 Patients may need year-round treatment rather than seasonal therapy.