Overview
Acute Sinusitis
Quick Reference
Critical Alerts
- Orbital and intracranial complications are emergencies: Orbital cellulitis, cavernous sinus thrombosis, brain abscess
- Most sinusitis is viral: Antibiotics not needed for most cases
- Bacterial more likely if symptoms >10 days or biphasic illness
- Amoxicillin-clavulanate is first-line antibiotic: When indicated
- Pain control and supportive care are mainstay: For viral sinusitis
- Red flags require urgent imaging and specialist referral
Viral vs Bacterial Sinusitis
| Feature | Viral | Bacterial |
|---|---|---|
| Duration | <10 days | >0 days without improvement |
| Onset | Gradual | Biphasic ("double sickening") |
| Fever | Low-grade or absent | May be high |
| Discharge | Clear → Purulent | Purulent |
| Facial pain | Mild | Severe, unilateral |
Emergency Treatments
| Condition | Treatment |
|---|---|
| Viral sinusitis | Supportive: saline irrigation, decongestants, analgesics |
| Bacterial sinusitis | Amoxicillin-clavulanate 875/125 mg BID × 5-7 days |
| Orbital complications | IV antibiotics, CT, ophthalmology/ENT consult |
| Intracranial complications | IV antibiotics, CT/MRI, neurosurgery consult |
Definition
Overview
Acute rhinosinusitis is inflammation of the nasal cavity and paranasal sinuses lasting <4 weeks. Most cases are viral and self-limited. Bacterial sinusitis occurs in ~2% of cases, typically as a secondary infection. Antibiotics are indicated only for bacterial sinusitis. Complications involving the orbit or brain are rare but serious.
Classification
By Duration:
| Type | Duration |
|---|---|
| Acute | <4 weeks |
| Subacute | 4-12 weeks |
| Chronic | >2 weeks |
| Recurrent acute | ≥4 episodes/year, each lasting <4 weeks, with complete resolution between |
By Etiology:
| Type | Features |
|---|---|
| Viral (most common) | Self-limited, resolves in 7-10 days |
| Bacterial | >0 days, biphasic course, severe symptoms |
| Fungal | Immunocompromised, or allergic fungal sinusitis |
Epidemiology
- Very common: ~31 million cases/year in US
- Viral predominates: 90-98% of acute sinusitis
- Bacterial: 0.5-2% of viral URIs progress to bacterial
- Leading cause of unnecessary antibiotic prescription
Etiology
Viral:
- Rhinovirus (most common)
- Influenza, parainfluenza
- Adenovirus, RSV
Bacterial:
| Organism | Frequency |
|---|---|
| Streptococcus pneumoniae | 30-40% |
| Haemophilus influenzae | 20-30% |
| Moraxella catarrhalis | 10-20% |
| Staphylococcus aureus | <10% |
Pathophysiology
Mechanism
- URI/Viral infection: Mucosal inflammation, edema
- Ostial obstruction: Blocked sinus drainage
- Mucus stasis: Trapped secretions
- Secondary bacterial infection: (If occurs) Bacterial overgrowth
- Purulent sinusitis: Inflammation, pain, discharge
Predisposing Factors
| Factor | Mechanism |
|---|---|
| URI | Mucosal edema |
| Allergic rhinitis | Chronic inflammation |
| Anatomic abnormalities | Septal deviation, polyps |
| Dental infection | Direct extension |
| Immunodeficiency | Impaired host defense |
Clinical Presentation
Symptoms
| Symptom | Description |
|---|---|
| Nasal congestion | Bilateral or unilateral |
| Purulent nasal discharge | May be anterior or posterior |
| Facial pain/pressure | Over affected sinus(es) |
| Headache | Frontal or maxillary |
| Hyposmia/Anosmia | Decreased sense of smell |
| Cough | Often postnasal drip |
| Fever | Variable; more common in bacterial |
| Tooth pain | Upper teeth (maxillary sinusitis) |
History
Key Questions:
Indicators of Bacterial Sinusitis:
- Symptoms >10 days without improvement
- Severe symptoms at onset (high fever ≥39°C + purulent discharge ≥3 days)
- "Double sickening": Initial improvement then worsening
Physical Examination
| Finding | Significance |
|---|---|
| Purulent rhinorrhea | Common in bacterial |
| Facial tenderness | Over affected sinus |
| Nasal mucosal edema | Swollen, erythematous |
| Post-nasal drip | Visible on oropharynx |
| Transillumination | Decreased (poor sensitivity) |
Duration of symptoms
Common presentation.
Character of nasal discharge
Common presentation.
Facial pain location
Common presentation.
Fever
Common presentation.
Pattern
Improving then worsening (biphasic)?
Prior episodes (recurrent)?
Common presentation.
Allergies
Common presentation.
Immunocompromise
Common presentation.
Red Flags
Complications Requiring Urgent Attention
| Finding | Concern | Action |
|---|---|---|
| Periorbital swelling/erythema | Preseptal cellulitis | CT, ophthalmology |
| Proptosis, ophthalmoplegia | Orbital cellulitis | Emergent CT, IV abx, ophthalmology |
| Diplopia | Orbital abscess | Emergent CT, surgery |
| Severe headache, high fever | Intracranial extension | CT/MRI, neurosurgery |
| Mental status changes | Meningitis, abscess | CT/MRI, LP, IV abx |
| Facial swelling (Pott's puffy tumor) | Frontal bone osteomyelitis | CT, surgery |
Differential Diagnosis
Other Causes of Nasal/Facial Symptoms
| Diagnosis | Features |
|---|---|
| Allergic rhinitis | Sneezing, itching, watery discharge, seasonality |
| Non-allergic rhinitis | No allergic triggers |
| Dental abscess | Tooth pain, localized swelling |
| Migraine or cluster headache | Neurological symptoms |
| Nasal polyps | Chronic congestion, anosmia |
| Tumor | Unilateral symptoms, bleeding |
Diagnostic Approach
Clinical Diagnosis
- Acute sinusitis is a clinical diagnosis
- No imaging needed for uncomplicated cases
Imaging
Not Indicated for Uncomplicated Sinusitis
Indications for CT Sinus:
| Indication | Notes |
|---|---|
| Suspected complications | Orbital, intracranial |
| Recurrent sinusitis | Anatomic evaluation |
| Failed treatment | Looking for other pathology |
| Chronic sinusitis | Pre-surgical planning |
Laboratory
- Not routinely needed
- Consider if immunocompromise or complications suspected
Treatment
Principles
- Distinguish viral from bacterial: Avoid unnecessary antibiotics
- Supportive care for viral sinusitis: Symptomatic relief
- Antibiotics only for bacterial sinusitis: When criteria met
- Watch for complications: Refer if concerning features
Viral Sinusitis (Supportive Care)
| Intervention | Details |
|---|---|
| Saline nasal irrigation | Saline rinses (neti pot, squeeze bottle) |
| Analgesics | Acetaminophen, ibuprofen |
| Intranasal corticosteroids | Fluticasone, mometasone (may help symptoms) |
| Decongestants | Pseudoephedrine PO or oxymetazoline nasal (limit to 3 days) |
| Hydration | Oral fluids |
Bacterial Sinusitis (Antibiotic Therapy)
Indications for Antibiotics:
- Symptoms >10 days without improvement
- Severe symptoms at onset (fever ≥39°C + purulent discharge ≥3 days)
- "Double sickening" (worsening after initial improvement)
First-Line:
| Agent | Dose | Duration |
|---|---|---|
| Amoxicillin-clavulanate | 875/125 mg BID or 2 g XR BID | 5-7 days |
Penicillin Allergy:
| Agent | Dose | Duration |
|---|---|---|
| Doxycycline | 100 mg BID or 200 mg daily | 5-7 days |
| Levofloxacin | 500 mg daily | 5-7 days |
| Moxifloxacin | 400 mg daily | 5-7 days |
Not Recommended First-Line:
- Amoxicillin alone (high resistance)
- TMP-SMX (high resistance)
- Macrolides (azithromycin—high resistance)
Adjunctive Therapy
| Intervention | Notes |
|---|---|
| Saline irrigation | Effective, recommended |
| Intranasal corticosteroids | May reduce symptoms |
| Oral corticosteroids | Limited evidence; consider for severe symptoms |
| Decongestants | Symptomatic relief; limit topical to 3 days |
| Antihistamines | Only if allergic component |
Complicated Sinusitis
Orbital Complications:
| Intervention | Details |
|---|---|
| CT orbits/sinuses | Urgent |
| IV antibiotics | Ampicillin-sulbactam or vancomycin + ceftriaxone + metronidazole |
| Ophthalmology consult | Urgent |
| Surgical drainage | If abscess |
Intracranial Complications:
| Intervention | Details |
|---|---|
| CT/MRI brain | Urgent |
| IV antibiotics | Broad-spectrum + CNS penetration |
| Neurosurgery consult | Urgent |
Disposition
Discharge Criteria
- Uncomplicated sinusitis
- No red flags
- Able to tolerate oral medications
- Follow-up arranged
Admission Criteria
- Orbital or intracranial complications
- Toxic appearance or sepsis
- Immunocompromised with severe infection
- Failed outpatient treatment with progression
Referral
| Indication | Referral |
|---|---|
| Orbital cellulitis | Ophthalmology, ENT (urgent) |
| Intracranial complications | Neurosurgery (emergent) |
| Recurrent or chronic sinusitis | ENT |
| Failed antibiotic therapy | ENT |
Patient Education
Condition Explanation
- "Sinus infections are usually caused by viruses and get better on their own."
- "Antibiotics only help if it's a bacterial infection, which is less common."
- "Saline rinses and decongestants can help relieve symptoms."
Home Care
- Use saline nasal rinses regularly
- Take pain relievers as needed
- Stay hydrated
- Avoid irritants (smoke)
- Use decongestants for no more than 3 days
Warning Signs to Return
- Swelling or redness around the eye
- Vision changes or double vision
- Severe headache or confusion
- Fever not improving or getting worse
- Symptoms worsening after initial improvement
Special Populations
Children
- More common in children
- Same principles apply
- Amoxicillin-clavulanate first-line if antibiotic indicated
- Watch for orbital complications (more common in children)
Immunocompromised
- Higher risk of complications
- Consider broader antibiotic coverage
- Lower threshold for imaging
- Watch for fungal sinusitis
Pregnant Women
- Saline irrigation is safe
- Avoid oral decongestants if possible
- Amoxicillin-clavulanate is safe if antibiotic needed
- Avoid fluoroquinolones
Quality Metrics
Performance Indicators
| Metric | Target | Rationale |
|---|---|---|
| Avoid antibiotics for viral sinusitis | >0% | Antibiotic stewardship |
| Amoxicillin-clavulanate as first-line | >0% | When antibiotic indicated |
| CT for suspected complications | 100% | Identify serious pathology |
| Red flag assessment documented | 100% | Safety |
Documentation Requirements
- Duration of symptoms
- Criteria for bacterial sinusitis (if antibiotics given)
- Red flag assessment
- Treatment and follow-up plan
Key Clinical Pearls
Diagnostic Pearls
- Most is viral: Antibiotics usually not needed
- >10 days = Consider bacterial: Or severe onset, or biphasic course
- No imaging for uncomplicated: Clinical diagnosis
- CT for complications: Orbital, intracranial
- Purulent discharge doesn't always mean bacterial: Can be late-stage viral
- Transillumination is unreliable: Don't rely on it
Treatment Pearls
- Saline irrigation is effective: And safe
- Amoxicillin-clavulanate first-line: When antibiotic needed
- Avoid macrolides: High resistance
- Short course (5-7 days): As effective as longer courses
- Limit topical decongestants to 3 days: Rebound congestion
- Intranasal steroids may help: Adjunctive benefit
Disposition Pearls
- Most can be discharged: With supportive care or antibiotics
- Admit for complications: Orbital, intracranial
- Refer recurrent cases to ENT: Anatomic evaluation
- Educate on appropriate antibiotic use: Stewardship
References
- Rosenfeld RM, et al. Clinical practice guideline (update): adult sinusitis. Otolaryngol Head Neck Surg. 2015;152(2 Suppl):S1-S39.
- Chow AW, et al. IDSA Clinical Practice Guideline for Acute Bacterial Rhinosinusitis in Children and Adults. Clin Infect Dis. 2012;54(8):e72-e112.
- Fokkens WJ, et al. European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) 2020. Rhinology. 2020;58(Suppl S29):1-464.
- Aring AM, et al. Diagnosis and Management of Acute Rhinosinusitis. Am Fam Physician. 2016;93(7):596-604.
- Lemiengre MB, et al. Antibiotics for acute rhinosinusitis in adults. Cochrane Database Syst Rev. 2018;9(9):CD006089.
- DeMuri GP, et al. Acute Bacterial Sinusitis. Infect Dis Clin North Am. 2019;33(3):713-730.
- AAP. Clinical practice guideline for the diagnosis and management of acute bacterial sinusitis. Pediatrics. 2013.
- UpToDate. Acute sinusitis and rhinosinusitis in adults. 2024.