Sinusitis

🔍 When to Suspect

Nasal congestion accompanied by facial pain or pressure (worse on bending forward) and/or a thick, purulent nasal discharge, often with a reduced sense of smell

From the full topic in The Ocean Library: Sinusitis

🧭 When to suspect

Acute sinusitis (acute rhinosinusitis) is a self-limiting inflammation of the paranasal sinuses and nasal lining, almost always triggered by a viral upper respiratory tract infection. It is acute when symptoms have lasted less than 12 weeks and chronic when they persist beyond 12 weeks without full resolution. The overwhelming majority of acute cases are viral, settle within 2 to 3 weeks, and improve without antibiotics – and withholding antibiotics rarely leads to complications.

Suspect acute sinusitis when there is nasal blockage (obstruction/congestion) or nasal discharge (anterior or posterior nasal drip), together with at least one of: facial pain or pressure (often frontal or maxillary, classically worse on bending forward, or headache), a reduced or lost sense of smell in adults, or a daytime and night-time cough in children. Discoloured (yellow or green) discharge is common in viral illness and does not, on its own, indicate a bacterial cause.

The two clinical tasks are to distinguish the rare bacterial case from the common viral one – which guides whether an antibiotic is ever appropriate – and to never miss a serious complication or a sinister unilateral presentation.

Viral acute sinusitis (the great majority)	Suggests a bacterial cause (≥ 2 features)
• Follows a cold; symptoms peak early and settle over 2–3 weeks.	• Symptoms > 10 days with little improvement.
• Mild–moderate, often bilateral facial pressure and congestion.	• Discoloured or purulent nasal discharge.
• Discharge may be discoloured – not a reliable marker of bacterial infection.	• Severe, localised unilateral pain (especially over the teeth or jaw).
• No high fever and no deterioration after an initial improvement.	• Fever > 38°C, or marked deterioration after an initial milder phase ("double-sickening").

🧠 Clinical pearl Truly unilateral sinonasal symptoms should make you think beyond simple infection. Consider an odontogenic (dental) cause – maxillary sinusitis arising from an infected upper molar – a foreign body in a young child, or, where symptoms are persistent with bloodstained discharge or crusting, a sinonasal malignancy. NICE itself flags dental infection as the alternative diagnosis to reconsider whenever sinusitis fails to settle.

Source: NICE NG79

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