Acute Sinusitis

Otolaryngology

Description

Acute sinusitis, also termed acute rhinosinusitis, is an abrupt inflammatory infection of the paranasal sinus cavities and contiguous nasal mucosa that lasts fewer than four weeks and is classically precipitated by an antecedent viral upper-respiratory tract infection; it encompasses both viral acute rhinosinusitis, which accounts for more than ninety percent of presentations, and acute bacterial rhinosinusitis, which develops in roughly two percent of symptomatic colds when secondary bacterial overgrowth by Streptococcus pneumoniae, nontypeable Haemophilus influenzae or Moraxella catarrhalis occurs.

Symptoms

Hallmark features include nasal congestion, purulent anterior or posterior rhinorrhea, facial pressure or pain that intensifies on bending forward, hyposmia or anosmia, and cough that worsens at night; systemic manifestations are low-grade fever, malaise or fatigue. Bacterial sinusitis is suggested by symptoms persisting beyond ten days without improvement, severe onset with fever above 39 °C and purulent nasal discharge for at least three consecutive days, or a “double-worsening” pattern in which a typical viral URI improves then abruptly deteriorates with new purulent drainage and facial pain. Maxillary disease produces cheek or upper-tooth pressure, ethmoiditis yields peri-orbital pain, frontal sinusitis causes forehead headache and sphenoid disease may present with vertex or occipital headache.

Risk Factors

Recent viral upper-respiratory infection, allergic rhinitis, chronic rhinitis, asthma, cigarette smoking, second-hand smoke exposure, anatomical variants such as septal deviation or concha bullosa, dental infection of maxillary molars, immunodeficiency, cystic fibrosis, ciliary dyskinesia, gastroesophageal reflux, mechanical ventilation, intranasal cocaine use and frequent swimming or diving heighten susceptibility to acute sinusitis.

Diagnosis

Diagnosis is clinical, integrating history and physical examination with anterior rhinoscopy that may reveal mucosal edema, mucopus in the middle meatus and reduced transillumination of the maxillary sinuses. Routine imaging and culture are unnecessary in uncomplicated cases; when complications or alternative diagnoses are considered, non-contrast sinus CT is the modality of choice because it delineates mucosal thickening, air-fluid levels and sinus opacification, while MRI is reserved for suspected intracranial or orbital extension. Nasal endoscopy with targeted middle-meatal culture assists in antibiotic-refractory disease or immunocompromised hosts. Laboratory inflammatory markers such as C-reactive protein have limited specificity but levels above 20 mg/L support bacterial etiology.

Treatment

Viral acute rhinosinusitis warrants symptomatic management with adequate hydration, antipyretics, analgesics, saline irrigation, topical or systemic decongestants for short courses, and intranasal corticosteroids such as fluticasone or mometasone that reduce mucosal edema and hasten recovery. Bacterial sinusitis in immunocompetent adults without severe disease may be treated with watchful waiting and rescue prescription, yet immediate antibiotics are indicated for severe illness, immunosuppression or failure of conservative therapy after seven days. First-line empiric therapy is high-dose amoxicillin-clavulanate 875–125 mg twice daily for five to seven days in adults and 45 mg/kg/day divided twice daily for ten days in children; doxycycline is an acceptable adult alternative, whereas respiratory fluoroquinolones are reserved for severe β-lactam allergy or multi-drug-resistant pneumococcus. Adjunct intranasal corticosteroids are recommended in both viral and bacterial infections and have synergistic benefit with antibiotics. Oral corticosteroids, antihistamines and mucolytics confer no consistent advantage and are not routinely advised. Surgical drainage via functional endoscopic sinus surgery is reserved for orbital or intracranial complications or chronic therapy-refractory disease.

Outlook

Most viral episodes resolve spontaneously within seven to ten days, and appropriately treated bacterial sinusitis achieves clinical cure in ninety percent of cases; recurrent or chronic sinusitis develops in a minority, often related to persistent risk factors. Early recognition of bacterial superinfection and judicious antibiotic use result in excellent long-term outcomes with preservation of sinus function.

Complications

Local spread may produce preseptal or orbital cellulitis, subperiosteal or orbital abscess, osteomyelitis of the frontal bone (Pott’s puffy tumor) or odontogenic maxillary sinusitis; intracranial complications include meningitis, epidural or subdural empyema, brain abscess and cavernous-sinus thrombosis; chronic mucosal inflammation can evolve into polyposis, mucocele formation or persistent anosmia, while antibiotic misuse may result in Clostridioides difficile colitis and resistant bacterial flora.

Prevention

Annual influenza vaccination, pneumococcal conjugate immunization according to schedule, aggressive management of allergic rhinitis with intranasal corticosteroids or allergen immunotherapy, smoking cessation, avoidance of environmental pollutants, hand hygiene to curtail viral transmission, proper dental hygiene, timely treatment of upper respiratory tract infections and postoperative care after nasal surgery reduce the incidence of acute sinusitis.

Support

Patients should maintain hydration, perform twice-daily isotonic saline irrigations, sleep with the head elevated, apply warm facial compresses, use intranasal corticosteroids as prescribed, avoid smoke and allergens, adhere to antibiotic regimens completely if started, and return for reassessment if symptoms fail to improve within forty-eight to seventy-two hours after antibiotics or if new focal neurologic or ocular findings emerge.