Sinusitis
Definition
Sinusitis is defined as symptomatic inflammation of the paranasal sinuses.
Acute sinusitis is usually triggered by a viral upper respiratory tract infection.
Symptoms and signs
- Nasal blockage 
- Nasal discharge or discoloured/purulent nasal discharge 
- Facial pain/pressure (or headache) 
- Reduction of the sense of smell 
- Tenderness over the sinuses 
- Fever 
Differential diagnosis
- Upper respiratory tract infection 
- Allergic rhinitis — usually restricted to nasal symptoms: sneezing; watery nasal discharge; nasal itching; and itchy, watery eyes. 
- Nasal foreign body — unilateral mucopurulent discharge or blockage (more common in children). 
- Adenoiditis and tonsillitis (particularly in children) 
- Sinonasal tumour — persistent unilateral symptoms, such as nasal obstruction, nasal discharge or nosebleeds, crusting, or facial swelling. 
- Turbinate hypertrophy — nasal obstruction is the predominant symptom. 
- Migraine 
- Giant cell arteritis (temporal arteritis) 
- Temporomandibular joint dysfunction. 
- Neuropathic or atypical facial pain such as trigeminal neuralgia. 
- Dental pain or dental abscess. 
Classification
Acute sinusitis
Symptoms last >10d but <12w
Objective evidence of sinonasal inflammation on examination.
Treatment
High-dose nasal corticosteroids
Antibiotics
Chronic sinusitis
Symptoms last>12 weeks
Predisposing factors:
Allergic rhinitis 
Asthma
Immunosuppression.
Treatment
Managing any associated conditions
Avoid allergic triggers.
Nasal irrigation with saline solution.
Intranasal corticosteroids 
Examination
- Inspecting and palpating the maxillofacial area to elicit swelling and tenderness. 
- Performing anterior rhinoscopy (using the largest speculum of an otoscope, or a head light and nasal speculum) to identify: 
- Signs which support a diagnosis of acute sinusitis such as nasal inflammation, mucosal oedema, and purulent nasal discharge. 
- Associated pathology such as nasal polyps, or anatomical abnormalities such as septal deviation. 
- Recording pulse rate, blood pressure, and temperature if the person is systemically unwell. 
Red Flag features warrant (urgent) referral to ENT
- Unilateral symptoms (increases suspicion of neoplasia) 
- Epistaxis 
- Blood-stained discharge 
- Crusting 
- Orbital symptoms (such as periorbital cellulitis, diplopia or reduced visual acuity) 
- Neurological symptoms or signs (symptoms or signs of meningitis). 
- Symptoms indicating a severe systemic infection 
- Persistent symptoms despite compliance with 3 months of treatment. 
- Nasal polyps complicating assessment or treatment, particularly if present in children. 
- Recurrent episodes of otitis media and pneumonia in a child. 
Treatment
Sinusitis symptoms<10d: antibiotics are usually not required
Sinusitis symptoms>10d:
- High-dose intranasal corticosteroid (mometasone or fluticasone) for 14 days. 
- Antibiotics (5-day course) 
No penicillin allergy
First line: phenoxymethylpenicillin, or if systemically very unwell co-amoxiclav.
Second line (no improvement with 2d antibiotic treatment): co-amoxiclav 
Penicillin allergy or intolerance
First line: doxycycline or clarithromycin (erythromycin in pregnancy).
Second line (no improvement with 2d antibiotic treatment): consult local microbiologist.
