EVIDENCE-BASEDAWAITING CLINICIAN REVIEW

Sinusitis

Sinusitis (rhinosinusitis) is inflammation of the nasal passages and paranasal sinuses. Most acute cases follow a viral upper-respiratory infection and improve without antibiotics, while a smaller proportion develop acute bacterial sinusitis; chronic rhinosinusitis is a different, longer-lasting inflammatory condition.

At a glance

Quick facts

Condition snapshot
Common name
Sinus infection
Most acute cases
Viral
Typical symptoms
Congestion · drainage · facial pressure
Diagnosis
Usually clinical
Imaging
Not routine uncomplicated acute disease
Antibiotics
Only selected likely bacterial cases

Names & terminology

How this entity may be named or searched

Rhinosinusitis
Preferred descriptive term because nasal and sinus inflammation usually occur together.
Acute viral rhinosinusitis
Symptoms associated with a viral upper-respiratory infection and usually self-limited.
Acute bacterial rhinosinusitis
A smaller subset suggested by persistent, severe or “double-worsening” symptoms.
Chronic rhinosinusitis
Symptoms and objective inflammation lasting at least about 12 weeks; this is not simply one prolonged bacterial cold.

Structured entity profile

Clinical profile

Condition data
Primary siteNose + paranasal sinusesInflammation blocks drainage and produces congestion and pressure.
Acute causeUsually viralAntibiotics are unnecessary for many acute sinus infections.
SymptomsCongestion, drainage, facial pressureCough, reduced smell and headache can occur.
DiagnosisClinical in uncomplicated acute diseaseDuration and pattern are more useful than mucus color alone.
ImagingReserved for selected casesCT is used for complications, recurrent/chronic disease or diagnostic uncertainty.
TreatmentSymptom care ± antibioticsAntibiotics are used when bacterial disease is sufficiently likely or complications are present.

Overview

The sinuses are air-filled spaces that drain into the nasal cavity. A viral cold, allergy or other inflammation can swell the lining and narrow drainage pathways, leading to congestion, pressure and retained mucus. This environment can occasionally support bacterial infection, but the majority of short-duration acute sinusitis is viral. [1] [2]

Symptoms alone overlap substantially. Thick, yellow or green mucus can occur with viral illness and does not by itself prove a bacterial infection. Clinicians instead pay attention to duration, severity and trajectory: symptoms that persist without improvement, are severe from the beginning, or improve and then distinctly worsen are more suggestive of bacterial disease. [1] [2]

Symptoms and warning signs

Common symptoms include stuffy or blocked nose, nasal discharge, postnasal drip, facial pain or pressure, headache, cough, reduced sense of smell, bad breath and sore throat. Fever can occur, especially with more severe acute infection. Chronic rhinosinusitis often emphasizes persistent congestion, drainage and impaired smell rather than high fever. Eye swelling, double vision, severe frontal headache, neurologic changes or systemic toxicity are red flags for uncommon but dangerous complications. [1] [2]

SYMPTOM MATRIX

Duration and trajectory matter more than mucus color

Most acute sinus symptoms are viral and resolve with supportive care.

Upper respiratory
Typical acute symptoms
  • Nasal congestion
  • Runny nose / thick drainage
  • Facial pain or pressure
  • Postnasal drip
  • Cough
  • Reduced smell
Features that may support bacterial disease
  • Symptoms persist without improvement
  • High fever with purulent discharge / facial pain
  • Clear improvement followed by new worsening
  • Marked unilateral facial or dental pain
Complication warning signs
  • Swelling or redness around an eye
  • Double vision or reduced vision
  • Severe frontal headache or neck stiffness
  • Confusion, focal neurologic symptoms or severe illness

Orbital and intracranial complications are rare but need urgent assessment.

Diagnosis

Uncomplicated acute sinusitis is usually diagnosed from the history and examination. Clinicians assess how long symptoms have lasted, whether they are improving, and whether there is a severe or double-worsening pattern. Mucus color alone is not a reliable discriminator between viral and bacterial infection. [1] [2]

Routine imaging is not recommended for uncomplicated acute rhinosinusitis. CT becomes useful when orbital/intracranial complications are suspected, when symptoms are recurrent or chronic, before selected surgery, or when another diagnosis needs to be clarified. Chronic rhinosinusitis generally requires objective evidence of sinonasal inflammation by endoscopy or CT in addition to persistent symptoms. [2] [3]

Diagnostic pathway

Use symptom duration and course to estimate bacterial probability

Imaging is for complications and chronic/recurrent disease—not routine colds.

Clinical diagnosis
1Define duration and severityDistinguish a short viral course from persistent, severe or double-worsening illness.
2Check red flagsEye findings, neurologic signs and systemic toxicity require urgent escalation.
3Treat uncomplicated disease clinicallyUse symptom-directed care and selective antibiotic strategies when bacterial disease is likely.
4Investigate chronic/recurrent symptomsConsider ENT review, nasal endoscopy, CT, allergy or immune evaluation when appropriate.
Routine acute imagingNot recommendedif uncomplicated
Chronic diseaseEndoscopy / CTobjective inflammation

A single symptom such as green mucus does not establish bacterial sinusitis.

Viral vs bacterial sinusitis

Acute viral rhinosinusitis usually improves as the underlying cold resolves. Bacterial sinusitis is more likely when symptoms persist without improvement beyond the expected viral course, when high fever and purulent drainage/facial pain are severe from the outset, or when a person first improves and then gets clearly worse (“double worsening”). Exact thresholds vary slightly among guidelines. [1] [2]

Chronic rhinosinusitis

Chronic rhinosinusitis is an inflammatory syndrome lasting about 12 weeks or longer, often with nasal obstruction, drainage, facial pressure and reduced smell. Polyps, asthma, allergy and other inflammatory traits may coexist. Management focuses on long-term anti-inflammatory and local therapy rather than repeated short antibiotic courses unless there is a separate bacterial exacerbation. [3]

Treatment and management

Many acute cases improve without antibiotics. Symptom care can include adequate fluids, saline nasal irrigation and analgesics; intranasal corticosteroids can be helpful, especially when allergy or chronic inflammation contributes. Decongestants may provide short-term relief for some adults but are not suitable for everyone, and topical nasal decongestants can cause rebound congestion if used too long. [1] [2]

When acute bacterial sinusitis is sufficiently likely, clinicians may use watchful waiting with reliable follow-up or prescribe antibiotics based on severity, comorbidity and guideline criteria. Antibiotics provide no benefit for purely viral disease and can cause adverse effects and antimicrobial resistance. Complicated sinusitis requires urgent specialist and hospital management. [1] [2]

Treatment & care hub

Relieve inflammation first; reserve antibiotics for likely bacterial disease

The treatment strategy follows cause, duration and complication risk.

Antibiotic stewardship
Supportive careMost acute cases

Control symptoms while viral disease resolves

Saline, pain relief and selected intranasal therapy are common approaches.

AntibioticsSelected

Treat likely bacterial infection

Persistent, severe or double-worsening patterns can justify antibiotics or structured watchful waiting.

Chronic diseaseLong term

Use anti-inflammatory management

Chronic rhinosinusitis often needs intranasal therapy and ENT/allergy evaluation rather than repeated antibiotics.

ComplicationsEmergency

Escalate eye or neurologic red flags

Orbital or intracranial spread requires urgent imaging and specialist care.

Define course→Check red flags→Treat symptoms→Use antibiotics selectively

Antibiotic choice and duration depend on local resistance, allergy history, age and comorbidity.

Reducing recurrence

Managing allergic rhinitis, avoiding smoking and secondhand smoke, using appropriate nasal anti-inflammatory treatment for chronic disease, and correcting structural or dental contributors when present can reduce recurrent symptoms. Repeated “sinus infections” without symptom-free intervals should prompt reconsideration of the diagnosis rather than automatic repeated antibiotics. [1] [3]

When to seek medical review

Clinical review is reasonable for severe symptoms, persistent symptoms without improvement, repeated episodes or significant comorbidity. Urgent care is needed for eye swelling, visual change, severe headache with neurologic signs, neck stiffness or marked systemic illness. [1] [2]

Antibiotic stewardship

Many sinus infections get better without antibiotics

CDC explicitly notes that antibiotics are not needed for many cases.

CDC — Sinus Infection Basics ↗
Most uncomplicated acute diseaseviral / self-limitedantibiotics often unnecessary
Routine imagingnot needed
Bacterial cluecourse + severity
Interpretation: Individual treatment depends on duration, severity, risk factors and follow-up reliability.

Common questions

Frequently asked questions

Reference content

Sources

  1. CDC — Sinus Infection Basics
  2. AAO-HNSF — Clinical Practice Guideline: Adult Sinusitis
  3. AAO-HNSF — Clinical Practice Guideline: Adult Sinusitis Update

This article is based on trusted medical sources and is awaiting clinician review. It is not a substitute for personalized medical advice.