Sinusitis

The nurse practitioner applies advanced clinical reasoning to sinusitis assessment, distinguishing acute (<4 weeks), subacute (4-12 weeks), chronic (>12 weeks), and recurrent acute (≥4 episodes/year with complete resolution between episodes) forms. The paranasal sinuses — maxillary, frontal, anterior ethmoid (draining through the ostiomeatal complex), posterior ethmoid, and sphenoid — are lined with pseudostratified ciliated columnar epithelium producing mucus that is swept toward the ostia by coordinated ciliary beating (mucociliary clearance). Sinusitis develops when ostial obstruction impairs drainage, creating a hypoxic, stagnant environment promoting bacterial growth. Chronic rhinosinusitis (CRS) is subdivided into CRS with nasal polyps (CRSwNP — eosinophilic/Type 2 inflammation, associated with asthma and aspirin-exacerbated respiratory disease/Samter triad) and CRS without nasal polyps (CRSsNP — mixed neutrophilic/lymphocytic inflammation). CRSwNP is driven by Type 2 immune responses (IL-4, IL-5, IL-13) with eosinophilic infiltration and is treated with intranasal corticosteroids, short courses of systemic steroids, and biologic therapy (dupilumab — anti-IL-4/IL-13 for refractory cases). CRSsNP often involves biofilm formation on sinus mucosa, making eradication difficult. Fungal sinusitis ranges from non-invasive (allergic fungal rhinosinusitis — AFRS, with eosinophilic mucin and fungal hyphae) to...