What causes chronic rhinorrhea in adults?

What Causes Chronic Rhinorrhea in Adults

Chronic rhinorrhea in adults results from multiple distinct etiologies that must be systematically differentiated: allergic rhinitis (IgE-mediated inflammation), nonallergic rhinitis subtypes (vasomotor, infectious, hormonal, drug-induced), chronic rhinosinusitis, anatomic abnormalities, and less commonly, cerebrospinal fluid leak or ciliary dysfunction.

Primary Etiologic Categories

Allergic Rhinitis

• IgE-mediated inflammation triggered by airborne allergens (pollens, dust mites, molds, animal dander) causes rhinorrhea accompanied by sneezing, nasal itching, and often ocular symptoms 1
• Typically develops before age 20 with seasonal exacerbations or perennial symptoms depending on allergen exposure 1
• Family history of atopy (allergic rhinitis, asthma, atopic dermatitis) strongly suggests allergic etiology 1
• Diagnosis requires correlation between symptom history after allergen exposure and positive specific IgE testing (skin prick or serum) 1, 2

Nonallergic Rhinitis (NAR)

• Vasomotor rhinitis (idiopathic nonallergic rhinitis) presents with rhinorrhea, congestion, and postnasal drip triggered by irritants (perfumes, tobacco smoke), temperature changes, humidity shifts, or barometric pressure differences 3, 4
• Drug-induced rhinitis occurs with ACE inhibitors, beta-blockers, alpha-receptor antagonists, phosphodiesterase-5 inhibitors, aspirin, and NSAIDs 5
• Rhinitis medicamentosa specifically results from rebound congestion after prolonged topical decongestant use (>3-5 days) or cocaine abuse 1, 5
• Hormonal rhinitis develops during pregnancy or with severe hypothyroidism 4
• Gustatory rhinitis causes isolated rhinorrhea associated with eating 1
• Nonallergic rhinitis with eosinophilia (NARES) shows eosinophils on nasal smear despite negative allergen testing 3, 4

Chronic Rhinosinusitis (CRS)

• Symptoms persisting >12 weeks include rhinorrhea, nasal congestion, facial pressure/pain, and postnasal drainage 1
• Predisposing factors include allergic rhinitis, asthma, nasal polyps, anatomic variants, and environmental exposures 1
• Affects 12% of US adults and requires differentiation from isolated viral upper respiratory infections 1

Anatomic Abnormalities

• Nasal septal deviation, turbinate hypertrophy, and nasal polyps cause mechanical obstruction with secondary rhinorrhea 1
• Severe deviated nasal septum may contribute to CRS development through altered aerodynamics and mucociliary clearance 6
• Unilateral symptoms suggest structural problems (polyp, foreign body, tumor) requiring urgent evaluation 1

Cerebrospinal Fluid (CSF) Rhinorrhea

• Refractory clear rhinorrhea, especially after head trauma or recent surgery, may indicate CSF leak 1
• Beta-2-transferrin testing in nasal secretions provides sensitive confirmation 1
• This represents a neurosurgical emergency requiring immediate evaluation

Ciliary Dysfunction

• Primary ciliary dyskinesia (PCD) or secondary ciliary dysfunction (post-viral) causes recurrent rhinosinusitis with impaired mucociliary clearance 1
• Consider in patients with recurrent infections, bronchiectasis, or situs inversus

Immunodeficiency

• Common variable immunodeficiency (CVID) affects 10% of patients with refractory CRS, with additional 6% having IgA deficiency 7
• Specific antibody deficiency (defective polysaccharide vaccine response despite normal IgG) occurs in 11% of surgical CRS failures 7
• Immunoglobulin deficiency present in 13-23% of recurrent or difficult-to-treat CRS cases 7

Critical Diagnostic Distinctions

Key Historical Features

• Pruritus and sneezing strongly favor allergic over nonallergic rhinitis 1
• Isolated postnasal drainage less likely represents allergic rhinitis 1
• Unilateral symptoms mandate evaluation for structural abnormality, foreign body, or neoplasm 1
• Clear, watery rhinorrhea after trauma requires CSF leak exclusion 1

Physical Examination Findings

• Mucosal appearance (pallor, edema, hyperemia) does not reliably distinguish allergic from nonallergic rhinitis 1
• Purulent nasal discharge suggests bacterial rhinosinusitis 1
• Nasal polyps associated with CRS, aspirin sensitivity, or eosinophilic disease 1

Common Pitfalls to Avoid

• Do not diagnose allergic rhinitis without confirming specific IgE sensitization through skin testing or serum testing, as symptoms overlap significantly with nonallergic causes 1, 2
• Avoid attributing rhinitis to uncommon medication causes (like statins) before excluding established culprits (ACE inhibitors, beta-blockers, topical decongestants) 5
• Do not miss CSF rhinorrhea in patients with persistent clear rhinorrhea and trauma/surgery history, as delayed diagnosis increases meningitis risk 1
• Screen for immunodeficiency when aggressive medical/surgical management fails or when rhinosinusitis associates with recurrent otitis, bronchiectasis, or pneumonia 7
• Recognize that imaging abnormalities alone are insufficient for CRS diagnosis, as paranasal sinus opacification occurs in healthy individuals and viral URI recovery 7