Acute rhinosinusitis
Inflammation of the nasal mucosa and paranasal sinuses that follows blockage of their narrow drainage pathways, almost always viral and self-limiting, with antibiotics reserved for the minority who develop true bacterial superinfection or complications.
In a nutshell
Acute rhinosinusitis usually follows a viral upper-respiratory infection and lasts two to three weeks. Use symptom duration and severity to guide antibiotics: most need self-care, prolonged uncomplicated disease may need no or back-up antibiotics, and orbital or intracranial signs need hospital referral.
Classic presentation
Nasal blockage or discharge with facial or dental pain or pressure and reduced smell after a cold; assess the duration, trajectory, systemic illness and eye or neurological signs.
Key points
- Most cases resolve over two to three weeks without antibiotics; symptoms for around 10 days or less should not receive an antibiotic.
- Bacterial disease is more likely when prolonged symptoms, purulent discharge, severe unilateral pain, fever and marked deterioration cluster, but no single feature is diagnostic.
- For prolonged symptoms without improvement, consider a high-dose intranasal corticosteroid for 14 days in adults and children aged 12 years or over.
- A back-up antibiotic is used if symptoms fail to improve within 7 days or worsen rapidly or significantly; reassess rather than automatically repeating treatment.
- Periorbital oedema, a displaced eye, double vision, ophthalmoplegia or reduced vision requires hospital referral.
- Frontal-bone swelling, meningism, severe frontal headache or focal neurological signs suggests intracranial complication and requires hospital referral.
- Topical nasal decongestants should not be used for more than 5 days.
First-line investigation
Clinical assessment alone for uncomplicated disease; arrange hospital assessment and specialist-led imaging when orbital or intracranial complications are suspected.
Management
Identify complications first
- Refer to hospital for severe systemic infection, orbital signs, newly reduced vision, frontal-bone swelling, meningism, severe frontal headache or focal neurological signs.1
Use self-care for short uncomplicated illness
Consider a nasal corticosteroid for prolonged symptoms
Use no, back-up or immediate antibiotics appropriately
Exam traps
- Antibiotics are not first-line for most acute rhinosinusitis, since the great majority is viral and self-limiting.
- A 'double-sickening' pattern raises the likelihood of bacterial disease but does not replace assessment for severe illness or complications.
- Periorbital swelling or eye signs require hospital referral, not simply escalation of oral antibiotics in the community.
- High-dose intranasal corticosteroid treatment is a consideration for prolonged symptoms in people aged 12 years or over, not routine treatment from day one.
Illustrations
Key sources
- NICE NG79: Sinusitis (acute): antimicrobial prescribing (Current UK recommendations for symptom duration, self-care, nasal corticosteroids, antibiotic strategy, antibiotic choice and hospital referral; page updated with 2026 changes.)
- NICE NG79: Symptoms and signs of acute sinusitis (UK bacterial-likelihood features and symptom-pattern guidance for acute sinusitis.)
- BNF online: analgesics, nasal corticosteroids, decongestants and antibacterials (Current UK prescribing, contraindication, interaction and dose cross-check; use the live monographs and NICE antimicrobial tables before prescribing.)
- NICE NG79: Update information (May 2026 update noting that topical nasal decongestants should not be used for more than 5 days.)
This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer. How our content is produced.

