Acute sinusitis

Definition and cause

Acute sinusitis is inflammation of one or more sinus cavities caused by infection or allergy. Most acute infectious cases are viral and resolve spontaneously within about 10 days.

Acute bacterial sinusitis may be primary, may complicate viral sinusitis, or may arise from dental infection. Common bacterial causes include Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.

The key decision is to distinguish viral rhinopharyngitis or viral sinusitis from bacterial sinusitis, because antibiotics are indicated only for likely bacterial disease or complications.

Clinical features

• Adults commonly have purulent unilateral or bilateral nasal discharge with nasal obstruction plus unilateral or bilateral facial pain that worsens on bending forward, maxillary tenderness, or frontal pain. Fever is often mild or absent.
• Children may have the same features but can also present with irritability, lethargy, cough, or vomiting.
• Severe paediatric infection may present with poor general condition, fever above 39 C, periorbital oedema, or facial oedema.
• Bacterial sinusitis is more likely when symptoms persist beyond 10 to 14 days, worsen after 5 to 7 days, or are severe from the start with high fever, severe pain, or general deterioration.

Assessment and differential diagnosis

• Assess duration, progression, fever height, facial pain severity, unilateral or bilateral discharge, dental pain or infection, eye symptoms, headache, vomiting, neck stiffness, immune suppression, sickle cell disease, asthma, and previous antibiotic use.
• Examine nasal cavity when feasible, face and periorbital tissues, oral cavity and teeth, throat, ears, chest, hydration, neurological status, and general appearance.
• Differentiate from common cold, allergic rhinitis, dental abscess, migraine, orbital cellulitis, meningitis, and other causes of facial pain or fever.
• Urgent referral is needed for ophthalmoplegia, dilated pupil, reduced visual acuity, corneal anaesthesia, periorbital swelling, meningeal signs, altered mental status, or severe systemic illness.

Symptomatic treatment

• Treat fever and pain using the Chapter 1 fever and pain pathways.
• Clear the nose with 0.9% sodium chloride. For a child, lay the child on the back with the head turned to the side and instil saline into each nostril.
• Encourage fluids, feeding, rest, and reassessment if symptoms worsen or fail to improve.
• If diagnosis is uncertain, symptoms are moderate and under 10 days, and reliable review is possible, start symptomatic treatment rather than antibiotics.

Antibiotic treatment

• Risk factors in children include immunosuppression, sickle cell disease, asthma, or other factors that increase complication risk.
• For sinusitis secondary to dental infection, arrange dental extraction or definitive dental care while giving antibiotic treatment.
• Infants with ethmoiditis or periorbital/orbital cellulitis need the eye/orbital cellulitis pathway and urgent care.

Complications, prevention, and follow-up

• Complications can include periorbital cellulitis, orbital cellulitis, abscess, osteitis, meningitis, intracranial spread, sepsis, and persistent dental infection.
• Refer for surgical drainage when ophthalmologic complications are present, including ophthalmoplegia, mydriasis, reduced visual acuity, or corneal anaesthesia.
• Review after 48 hours of antibiotics if symptoms are severe or not improving. Earlier review is needed for eye swelling, vision symptoms, severe headache, vomiting, confusion, neck stiffness, or worsening general condition.
• Prevention includes timely management of colds and dental infection, reducing smoke exposure, managing allergic rhinitis when present, vaccination according to local schedule, and clear return precautions.
• Handover should include symptom duration, severity criteria, eye and neurological findings, dental findings, antibiotic started, allergy history, risk factors, and response at reassessment.