Sinusitis is a common condition affecting 15% of the population in the developed world. Inflammation leads to sinus cavity obstruction and subsequent secondary infection (acute sinusitis) or chronic inflammation (chronic sinusitis).
Acute sinusitis will usually follow a URTI and presenting symptoms include nasal blockage (obstruction or congestion) or nasal discharge (anterior or posterior), with facial pain or pressure. There is usually a reduction in sense of smell.
The nasal discharge is purulent and the nasal blockage bilateral. Facial pain may be localised over the infected sinus or referred to the teeth, upper jaw, eye or forehead.
The pain may be worse when bending forward. Isolated facial pain in the absence of other symptoms is unlikely to be sinusitis.
Most commonly, patients present with slow resolving cold symptoms or worsening symptoms over five to six days. There may be a biphasic presentation, with the initial viral illness (rhinitis) appearing to settle before the patient starts to feel unwell with symptoms relating to the sinusitis.
Chronic sinusitis presents with nasal blockage or discharge with facial pain and reduction in sense of smell lasting longer than 90 days. With chronic sinusitis, facial pain is less common and loss of sense of smell is more commonly described.
There may be episodes of acute sinusitis experienced against the normal background of persistent symptoms.
With chronic symptoms, there is loss of ostial patency as a result of acute infections. This affects the ability of the sinuses to drain, resulting in chronic inflammation.
Chronic sinusitis may be associated with nasal polyps, especially in those with coexistent asthma (7-14% have polyps) and those hypersensitive to NSAIDs (30-60% have polyps).
Examination of the nose may reveal purulent discharge (Photograph: CC, ISM/Science Photo Library)
The most helpful examination in general practice is palpation of the sinuses, coupled with an external and internal examination of the nose using a light and speculum. With the exception of the sphenoid sinus, all of the sinuses can be palpated for tenderness.
The frontal sinus is palpated by pressure upwards against the medial side of the supraorbital ridge. Palpate the maxillary sinus against its anterior wall by pressure below the inferior orbital margin. The ethmoidal sinus can be palpated by pressing medially against the medial wall of the orbit.
Examination of the nose may reveal the presence of purulent discharge and oedema of the nasal mucosa. Investigations are not usually necessary to diagnose acute sinusitis.
In chronic sinusitis, internal inspection of the nose may reveal predisposing factors such as nasal polyposis or a deviated nasal septum. Polyposis usually has to be quite significant before it can be detected in primary care.
Polyps can be distinguished from the inferior turbinate by their colour (yellow-grey) and their lack of sensitivity to painful stimuli. They can also be compressed against the nasal mucosa with a cottonwool bud.
The examination should also include an assessment for other conditions predisposing to chronic sinusitis.
These include chronic dental infection (associated with 5-10% of chronic sinusitis cases), allergic rhinitis, asthma and sinonasal foreign bodies and tumours.
Most cases of acute sinusitis can be managed in primary care. The natural course of the illness is 2.5 weeks and it can be managed with simple analgesia, saline irrigation and a nasal decongestant if nasal blockage is problematic (maximum duration of use one week). Intranasal/oral corticosteroids and steam inhalation are no longer recommended.
Patients with severe systemic infection or a suspicion of intracranial or orbital spread should be admitted. An antibiotic should be prescribed if the patient is unwell but not requiring admission. Amoxicillin (1g three times daily for seven days) is an appropriate first-line choice with doxycycline (200mg immediately, 100mg once daily for seven days) or erythromycin in penicillin-allergic patients or pregnant women.
High-dose co-amoxiclav (500/125mg three times daily for seven days) is a useful second-line treatment for patients responding poorly to first-line therapies.
In chronic sinusitis, treatment of any associated condition, such as allergic rhinitis, is likely to benefit sinusitis symptoms. The patient should be advised to stop smoking and practise good dental hygiene.
In the case of allergic rhinitis, a three-month trial of an intranasal corticosteroid may prove helpful. Patients with nasal polyps can also be treated with intranasal corticosteroids, although polyps causing significant obstruction may need to be removed surgically.
Saline irrigation is helpful to relieve nasal congestion and short-term antibiotic treatment may be helpful for recurrent acute episodes.
Factors that predispose to sinus inflammation include:
Referral criteria for chronic sinusitis include suspected sinonasal tumour (persistent unilateral symptoms, bloodstained discharge or unilateral nasal polyps), frequent attacks of acute sinusitis which are troublesome (more than three courses of antibiotics per year), and nasal polyps causing significant obstruction.
- Dr Croton is a GP in Birmingham