What is causing a patient's foul odor sensation and red nose?

Nasal Foreign Body Until Proven Otherwise

A patient presenting with foul-smelling odor sensation and nasal redness should be immediately evaluated for a nasal foreign body, which is the most critical diagnosis to exclude given the risk of serious complications including tissue necrosis, septal perforation, and sinusitis. 1

Immediate Diagnostic Approach

Primary Concern: Nasal Foreign Body

• Unilateral foul-smelling nasal discharge is pathognomonic for nasal foreign body, particularly in children but can occur in adults 1, 2
• The combination of foul odor and nasal erythema (redness) strongly suggests retained foreign material with secondary infection 1
• Delay in diagnosis leads to significant morbidity including nasal infection, sinusitis, septal perforation, and synechiae formation 1
• Disk batteries are particularly dangerous, causing tissue necrosis and septal perforation in as little as 3 hours 1

Required Examination

• Perform nasal endoscopy immediately or refer urgently to a clinician who can perform it 1
• Anterior rhinoscopy alone is insufficient—nasal endoscopy allows complete visualization of the nasal cavity to identify foreign bodies not visible on routine examination 1
• The American Academy of Otolaryngology-Head and Neck Surgery recommends nasal endoscopy for any patient with unilateral symptoms or concern for unrecognized pathology 1

Secondary Differential Diagnoses

Atrophic Rhinitis

• Characterized by foul odor (ozena), crusting, and nasal inflammation 1
• Treatment involves continuous nasal hygiene with nasal lavage, crust debridement, and topical/systemic antibiotics when purulent secretions are present 1
• This is a chronic condition, not an acute presentation 1

Bacterial Rhinosinusitis

• Acute bacterial sinusitis presents with mucopurulent discharge, nasal congestion, facial pain/pressure, and headache 1
• Common pathogens include Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis 3
• Anaerobic bacteria (Prevotella, Porphyromonas, Fusobacterium) are main isolates in chronic sinusitis and produce foul odor 3

Rhinolith Formation

• Results from neglected nasal foreign bodies that gradually calcify and increase in size 2
• Presents with persistent foul-smelling unilateral nasal discharge and nasal obstruction 2
• This is essentially a chronic foreign body that has mineralized 2

Nasal Masses (Less Likely but Critical)

• Unilateral symptoms mandate evaluation for structural abnormality or neoplasm 4
• Nasal malignancies present with unilateral obstruction (66.7%) and epistaxis (55%), and may cause secondary infection with foul discharge 1
• Pyogenic granuloma and other benign lesions can cause similar symptoms 1

Clinical Algorithm

1. Immediate nasal endoscopy to visualize entire nasal cavity 1

   • If foreign body identified: remove immediately
   • If disk battery suspected: emergent removal required 1

2. If no foreign body visualized:

   • Assess for nasal masses, polyps, or structural abnormalities 1, 4
   • Consider CT imaging if endoscopy is unrevealing but symptoms persist 1

3. If infectious etiology suspected:

   • Treat bacterial rhinosinusitis with appropriate antibiotics 3
   • For atrophic rhinitis: initiate nasal hygiene regimen with saline lavage and consider antibiotics for purulent secretions 1

Critical Pitfalls to Avoid

• Never assume viral upper respiratory infection in the presence of foul odor—this symptom demands investigation for foreign body or bacterial infection 1, 2
• Do not rely on anterior rhinoscopy alone—87-93% of pathology can be localized with nasal endoscopy versus limited visualization with anterior examination 1
• Unilateral symptoms are red flags requiring thorough evaluation to exclude foreign body, mass, or structural abnormality 1, 4
• In children, maintain high suspicion for foreign body even if history is unclear—parents may be unaware of the inciting event 1