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HelenaLiira

Diagnosis of Acute Sinusitis

Acute rhinosinusitis is most often a self-limiting disease, in the treatment of which antibiotics are of little significance Antimicrobial Therapy for Acute Maxillary Sinusitis.
If sinusitis is suspected, sinus ultrasound is the method of choice because of its safety (no irradiation).
A sinus x-ray should be taken if the symptoms persist or recur, especially if they are unilateral, suggesting chronic sinusitis or some specific cause.
Negative findings on sinus ultrasonography in a patient with good general condition give strong grounds to abstain from prescribing antimicrobial treatment.
Sinusitis in children, see Sinusitis in Children.

It is not possible to differentiate between viral and bacterial sinusitis on grounds of clinical examination. Clinical examination is inaccurate in the diagnostics of sinusitis Clinical Examination in the Diagnosis of Sinusitis.
The goal of clinical examination is to identify other possible, severe causes or a rapidly progressing purulent sinusitis; these may be suggested by worsened general condition, severe local pain or swelling as well as fever.
If the patient presents with purulent discharge draining in the back of the throat, antimicrobial treatment may be beneficial The Prognostic Value of Symptoms and Clinical Signs of Acute Maxillary Sinusitis.

In experienced hands, the sensitivity and specificity of a properly performed sinus ultrasound examination are comparable to those of a sinus x-ray when compared with maxillary sinus puncture findings in the diagnostics of acute sinusitis Sinus Ultrasound and Radiography in the Diagnosis of Sinusitis.
Fluid retention is common in maxillary sinuses in the first days of common cold Sinusitis in the Common Cold. Sinus ultrasound should generally only be used to examine patients with symptoms that have lasted for more than one week.

See picture Investigation of Maxillary Sinuses by Ultrasonography.
The probe should not cross the line between the outer corner of the eye and the mouth angle. The lower border of the probe should not cross the line level with the tip of the nose. Examining outside these boundaries may give false positive findings.
The examination is started near the nose, with the lower border or the probe level with the tip of the nose. The probe is held in place while its axis is turned from one side to another so that the sound beam is certain to hit the back wall of the maxillary sinus perpendicularly. If no back wall echo is observed, the position of the probe is changed until the entire allowed area has been examined.

If there is fluid in the maxillary sinus, a single echo is seen 3-5 cm from the baseline (back wall echo). A back wall echo without intervening echoes is a positive finding (picture Investigation of Maxillary Sinuses by Ultrasonography (Close View), video Maxillary Sinus Ultrasonography).
Multiple echoes near the baseline suggest thickened mucosal lining and are not diagnostic for acute sinusitis.
Low echoes repeated with regular intervals are usually so called multiplied echoes. There is probably no fluid and the finding is interpreted as negative.

The patient's symptoms strongly suggest maxillary sinusitis even if findings at ultrasonography are negative.
- If antimicrobial treatment is in any case to be prescribed (symptoms of lower respiratory tract infection, otitis media, tonsillitis), sinus x-ray is often not warranted.
Chronic sinusitis is suspected e.g. as the cause of persistent asthmatic symptoms. The mucosal lining of the sinus may be thick and inflamed without fluid visible as an echo.
Multiple front wall echoes (possibly suggesting a neoplasm) from some other location than only the lower part of the sinus
Often recurring or chronic sinusitis, especially in the assessment of unilateral symptoms
Before sending the patient to specialized care

van den Broek MF, Gudden C, Kluijfhout WP ym. No evidence for distinguishing bacterial from viral acute rhinosinusitis using symptom duration and purulent rhinorrhea: a systematic review of the evidence base. Otolaryngol Head Neck Surg 2014;150(4):533-7. [PubMed]
Hauer AJ, Luiten EL, van Erp NF ym. No evidence for distinguishing bacterial from viral acute rhinosinusitis using fever and facial/dental pain: a systematic review of the evidence base. Otolaryngol Head Neck Surg 2014;150(1):28-33. [PubMed]