Sinusitis
Overview
Sinusitis, more accurately termed rhinosinusitis, is a common PANCE topic that blends infectious disease, allergy/immunology, ENT, and primary care management. Understanding classification, diagnostic criteria, red flags, and first-line treatment is essential for exam success and clinical practice.
Pathophysiology
Sinusitis can be further divided into acute (1-4 weeks), subacute (4-12 weeks), and chronic (12 weeks and longer). Viral etiologies causing acute sinusitis usually follow upper respiratory infection including rhinovirus, influenza, and parainfluenza. The most common bacterial culprits are Steptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Infection from one of these can result in inflammation of the nasal cavity and paranasal sinuses with the order of most frequently involved sinuses being 1) Maxillary 2) Ethmoid 3) Frontal 4) Sphenoid.
Chronic sinusitis include similar symptoms as acute sinusitis with the exception of patients endorsing symptoms for 12 weeks or greater. Most common culprits behind chronic sinusitis are Staphylococcus aureus for bacterial infections, Aspergillus or Murcormycosis causing a fungal infection, and other etiologies such as allergic rhinitis, nasal polyps which can obstruct the draining sinuses, asthma, and immunodeficiency. Fungal infections commonly affect patient who are immunocompromised.
Clinical Manifestation
Classical symptoms include sinus pain/pressure which becomes worse when bending or leaning over, purulent sputum or nasal drainage, fever, inflamed or tender nasal cavity, and headache.
Maxillary — Cheek and upper incisors
Ethmoid — Between the eyes
Frontal — Forehead
Sphenoid — vertex of occiput
Diagnosis
Sinusitis is usually a clinical diagnosis made with a thorough review of systems and exam with symptoms being present for at least 1 week. A CT scan of the sinuses is the textbook diagnostic test of choice, but may be a little overkill in the family medicine setting. Sinus radiographs including Water’s view can also show sinusitis by looking for an air fluid level within the sinuses and may be more feasible for some patients. Water’s view is essentially an x-ray taken with the patient’s chin tilted up to give an adequate view of the sinus cavities.
Treatment
Symptomatic therapy is the first goal when treating acute sinusitis including decongestants, antihistamines, mucolytics, intranasal corticosteroids, analgesics, or nasal lavage. Many of these treatments can be obtained over the counter. Antibiotic therapy may be used for patients with symptoms present for at least 10-14 days with Amoxicillin being the first line antibiotic of choice. Second line choices may include doxycycline or trimethoprim-sulfamethoxazole (Bactrim). For chronic infections IV Amphotericin B is the 1st line treatment for fungal infections and surgical debridement may be necessary in severe cases.
Quiz Question
A 41-year-old woman presents to the clinic with 12 days of nasal congestion, purulent nasal discharge, facial pressure, and fatigue. She initially had symptoms of a “common cold” that seemed to improve after 5 days, but over the past 3 days her symptoms have worsened. She now reports a fever of 39°C (102.2°F) and increasing left maxillary facial pain radiating to her upper teeth.
Physical examination reveals purulent discharge in the left nasal passage and tenderness to palpation over the left maxillary sinus. Extraocular movements are intact and there is no periorbital edema.
What is the most appropriate next step in management?
A. Order CT scan of the sinuses
B. Start intranasal corticosteroids alone
C. Prescribe amoxicillin-clavulanate
D. Prescribe azithromycin
E. Reassure the patient and continue supportive care
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The correct answer is: C. Prescribe amoxicillin or amoxicillin-clavulanate (Augmentin)