Nasal Infections — Clinical Overview

1. Differential Diagnosis / Classification

2. Nasal Vestibulitis & Furunculosis

Nasal Vestibulitis (Folliculitis)

• Infection of the vestibular skin and hair follicles; nearly always S. aureus
• Risk factors: digital trauma (nose picking), excessive nose blowing, chemotherapy (taxanes, bevacizumab cause epithelial damage → secondary infection in >70–80%)
• Symptoms: anterior nasal pain, swelling, tenderness on palpation/nose movement, crusting, pustules; nasal septum typically spared
• Treatment: warm compresses + topical antimicrobials (mupirocin, retapamulin, polymyxin-B/bacitracin/neomycin)

Furunculosis

• Deep variety — perifollicular erythema, edema, ± abscess
• Complication: spread to facial cellulitis → cavernous sinus thrombosis (via anastomosis of facial vein with cavernous sinus — hence the "danger triangle" warning against squeezing nasal furuncles)
• Treatment: topical antimicrobials + oral anti-staphylococcal antibiotics + warm compresses + prompt incision & drainage if fluctuant

⚠️ Carbuncle = coalescence of multiple furuncles.

3. Acute Rhinosinusitis (ARS)

Definitions

• Acute: < 4 weeks | Subacute: 4–12 weeks | Chronic: ≥ 12 weeks
• Recurrent acute: ≥ 4 episodes/year with symptom-free intervals

Etiology

• Viral causes dominate: < 2% of sinusitis episodes are bacterial, yet antibiotics are prescribed at >70% of office visits — a major driver of overuse
• Most common bacteria: S. pneumoniae, H. influenzae, M. catarrhalis

Symptoms

• Purulent nasal discharge, facial congestion/fullness, facial pain/pressure
• Fever, hyposmia/anosmia, ear fullness, postnasal drip, halitosis, maxillary toothache, cough, fatigue
• Risk factors: age 45–65, smoking, asthma, air travel, allergies
• Exam: rhinoscopy shows excess mucus/purulence; tenderness over maxillary sinuses; sinus transillumination is not accurate

Complications (rare but serious)

• Orbital cellulitis, osteomyelitis, meningitis, intracranial abscesses, cavernous sinus thrombosis
• Red flags: confusion, unilateral weakness, proptosis, limited ocular movement, acute vision change

Antibiotic Prescribing Criteria (Table 37-2, Harrison's 22e)

Treatment

• Intranasal decongestants (oxymetazoline 2 sprays each nostril BID ≤ 5 days)
• Oral decongestants (pseudoephedrine 120 mg q12h)
• Analgesics/antipyretics (acetaminophen, NSAIDs)
• Nasal saline spray/washes
• Intranasal glucocorticoids (especially for allergic component)

• 1st line: amoxicillin/clavulanate 875/125 mg PO BID × 7 days
• Mild PCN allergy: cefuroxime
• Severe PCN allergy: doxycycline
• Macrolides: specifically NOT recommended (high rates of resistant S. pneumoniae)
• If no improvement after 3–5 days → 2nd line: amoxicillin/clavulanate 2000/125 mg BID or levofloxacin
• No improvement on 2nd-line → refer to ENT ± noncontrast CT

4. Chronic Rhinosinusitis (CRS)

Etiology

• Primarily inflammatory disease; bacterial colonization (S. aureus, gram-negatives), allergens (dust mites, mold, tobacco smoke), impaired mucociliary clearance (cystic fibrosis), immunodeficiency
• Often coexists with allergic rhinitis and asthma

Three Main Types (decreasing frequency)

Evaluation

• Anterior rhinoscopy: polyps appear white/gray/tan translucent in middle meatus
• Imaging: noncontrast CT of sinuses (preferred)
• Unilateral symptoms/polyps with bloody discharge → concern for tumor

Treatment of CRS

• Trigger avoidance (allergens, smoke)
• Saline irrigation (high-volume most effective)
• Intranasal glucocorticoids (mometasone, fluticasone; budesonide rinses for polyps) — reduce polyp size
• Oral glucocorticoids 2–3 weeks for polyp-predominant disease unresponsive to sprays
• Antihistamines, montelukast for allergic component
• Antibiotics: little evidence for routine use; 3 months of macrolides has modest benefit in CRS without polyps
• Functional endoscopic sinus surgery (FESS): for CRS unresponsive to medical therapy
• AFRS: requires surgical debridement

5. Invasive Fungal Sinusitis — Emergency

• Occurs in immunocompromised patients: uncontrolled diabetes, transplant recipients, hematologic malignancy, prolonged neutropenia
• Organisms: Mucorales (mucormycosis) and Aspergillus
• Clinical course: rapid progression — initial rhinosinusitis with facial pain/headache/fever → within days: cranial nerve involvement, orbital swelling, cellulitis, proptosis, chemosis, ophthalmoplegia; may be critically ill
• Evaluation: nasal endoscopy with biopsy + gadolinium-enhanced MRI (modality of choice for delineating extent)
• Treatment: IV antifungal agents (amphotericin B for Mucorales; voriconazole or amphotericin B for Aspergillus) + urgent surgical debridement; treat underlying immunosuppression (optimize glycemia in diabetics)

6. Nosocomial Sinusitis

• Occurs in critically ill patients, especially with nasotracheal intubation (tube obstructs sinus ostia)
• Consider in hospitalized patients with fever without identified source
• Management: remove precipitating factors (convert to orotracheal/tracheostomy) + empiric broad-spectrum antibiotics pending cultures

Quick Summary Table