top of page

Doctor, how do I treat my sinus infection? Is it a virus? Or something more serious?

Updated: Sep 12, 2023

Good morning, and TGIF! Welcome back to Dr Euan's ENT blog!

For today's blog post topic, we are going to look more closely into sinus infections.

Q: WHAT IS ACUTE SINUSITIS? or Acute upper respiratory tract infections?

Acute sinusitis is an inflammation of the sinuses. Because sinus passages are contiguous with the nasal passages, rhino-sinusitis is often a more appropriate term. Acute rhino-sinusitis is a common diagnosis, accounting for approximately 30 million primary care visits and $11 billion in healthcare expenditure annually.

It is also a common reason for antibiotic prescriptions in the United States and worldwide.

Due to recent guidelines and concerns for antibiotic resistance and the judicious use of antibiotics, it is essential to have clear treatment algorithms available for such a common diagnosis.

Rhino-sinusitis can be classified into the following groups (based more on consensus rather than empirical research) :

  1. Acute - symptoms lasting less than 4 weeks

  2. Subacute - symptoms last between 4 and 12 weeks

  3. Chronic - symptoms lasting more than 12 weeks

  4. Recurrent - four episodes lasting less than 4 weeks with complete symptom resolution between episodes

This is the terminology your GP/ENT Specialist may use when he/she is taking your clinical history in the clinic.


An image of the molecular model of Adenovirus

Viruses are the most common cause of acute rhino-sinusitis.

The viral rhino-sinusitis (VRS) pathogens include rhinovirus, adenovirus, influenza virus, and parainfluenza virus.

Sometimes, the viral infection is superseded by bacterial infections, when the mucus turns yellow/green or a dirty colour.

The most common causes of acute bacterial rhino-sinusitis (ABRS) are Streptococcus pneumoniae (38%), Haemophilus influenzae (36%), and Moraxella catarrhalis (16%).

Although rare, fungal infections can also cause acute rhino-sinusitis, though this is almost exclusively seen in the immunosuppressed (uncontrolled diabetes mellitus, HIV positive, oncology patients undergoing active treatment, and patients on immunosuppressants for an organ transplant or rheumatologic conditions). Typical species include Mucor, Rhizopus, Rhizomucor, and Aspergillus.

Acute rhino-sinusitis accounts for 1 in 5 antibiotic prescriptions for adults, making it the fifth most common reason for an antibiotic prescription.

Approximately 6% to 7% of children with respiratory symptoms have acute rhino-sinusitis. An estimated 16%

of adults are diagnosed with Acute Bacterial Rhino-Sinusitis (ABRS) annually. Given the clinical nature of this diagnosis, there is a possibility of overestimation.

An estimated 0.5 to 2.0% of viral rhino-sinusitis (VRS) will develop into bacterial infections in adults and 5 to 10% in children


Dr Euan Murugasu in consultation with the patient

History Taking and Clinical Examination:

Acute rhino-sinusitis is a clinical diagnosis.

Three “cardinal” symptoms that are most sensitive and specific for acute rhino-sinusitis are purulent nasal drainage accompanied by either nasal obstruction or facial pain/pressure/fullness. This must be elucidated specifically from patients who will present with generic "headache" complaints.

Isolated headache is not a symptom of sinusitis (with the rare exception of sphenoid sinusitis, which can present as an occipital or vertex headache and is usually chronic), but facial pressure is. The astute clinician must elicit this history from the patient to determine the exact symptoms they are experiencing.

When cardinal symptoms persist beyond ten days or if they worsen after an initial period of improvement (“double worsening”), one may diagnose ABRS.

Other symptoms associated with acute rhinosinusitis include cough, fatigue, hyposmia, anosmia, maxillary dental pain, and ear fullness or pressure. Anterior rhinoscopy may reveal mucopus emanating from the osteomeatal complex, or this may be demonstrated on formal endoscopic rhinoscopy in the clinic.

Children have a slight variance in the clinical presentation of ABRS. In addition to the 10-day duration, cardinal symptoms, and “double worsening,” children are more likely to present with fevers. Nasal discharge may initially be watery, then turn purulent. A viral upper respiratory infection precedes approximately 80% of acute bacterial sinusitis.

Severe symptoms are more indicative of a bacterial cause. These include high fevers (over 39 C or 102 F) accompanied by purulent nasal discharge or facial pain for three to four consecutive days at the beginning of the illness. Viral illnesses typically resolve after three to five days.

Acute rhino-sinusitis is a clinical diagnosis.

The clinician most commonly needs to distinguish between Viral Rhino- Sinuusitis (VRS) and ABRS, which is important so as to ensure the responsible usage of antibiotics. Local resistance patterns and prevalence of penicillin non-susceptible S. pneumoniae requires elucidation.

Conventional diagnostic criteria for rhino-sinusitis in adults is the patient having at least two major or one major plus two or more minor symptoms. The criteria in children are similar except that there is more of an emphasis on nasal discharge (rather than nasal obstruction).

Major symptoms include:

  • Purulent anterior nasal discharge

  • Purulent or dis-coloured posterior nasal discharge

  • Nasal congestion or obstruction

  • Facial congestion or fullness

  • Facial pain or pressure

  • Hyposmia or anosmia

  • Fever (for acute sinusitis only)

Minor symptoms:

  • Headache

  • Ear pain or pressure or fullness

  • Halitosis

  • Dental pain

  • Cough

  • Fever (for subacute or chronic sinusitis)

  • Fatigue

ABRS can be differentiated from VRS using the following clinical guidance:

  • Duration of symptoms for more than ten days

  • High fever (over 39 C or 102 F) with purulent nasal discharge or facial pain that lasts for 3 to 4 consecutive days at the beginning of the illness

  • Double worsening of symptoms within the first ten days


The patient using a nasal rinse

Treatment of ABRS consists of either antibiotic therapy or a period of watchful waiting so long as the certainty of reliable follow-up. There are slight variations between different expert committee guidelines

The American Academy of Otolaryngology Adult Sinusitis (2015) updated guideline recommends amoxicillin with or without clavulanate in adults as first-line therapy for a period of 5 to 10 days in most adults. Treatment failure is noted if symptoms do not decrease within 7 days or worsen at any time.

The Infectious Disease Society of America Guidelines for Acute Bacterial Rhinosinusitis recommends amoxicillin with clavulanate in adults as first-line therapy for 10 to 14 days in children and 5 to 7 days in adults. Treatment failure is noted if symptoms do not decrease after 3 to 5 days or worsen after 48 to 72 hours of therapy.

The American Academy of Pediatrics Clinic Practice Guideline for the Diagnosis and Management of Acute Bacterial Sinusitis in Children Aged to 18 Years recommends amoxicillin with or without clavulanate as first-line therapy. The duration of treatment is unclear, however treating for an additional seven days after symptoms resolve was their suggestion.

The criteria for treatment failure is if symptoms do not decrease or worsen after 72 hours of therapy. If the patient cannot tolerate oral fluids, then the patient can receive ceftriaxone 50m/kg. If the patient can tolerate oral fluids the next day and improves, then the patient can transition to an oral antibiotic course thereafter. A separate article recommended amoxicillin with clavulanate as initial therapy in children to adequately cover beta-lactamase-producing pathogens.

Local antibiotic resistance patterns, the patient's risk level, risk factors for antibiotic resistance, and severity of symptoms help determine whether to add clavulanate or whether high-dose amoxicillin (90mg/kg/day versus 45mg/kg/day) should be used in children.

For patients allergic to penicillin, a third-generation cephalosporin plus clindamycin (for adequate coverage of non-susceptible S. pneumoniae) or doxycycline could be therapeutic possibilities. Third-generation cephalosporins alone have variable efficacy rates against S. pneumoniae. Fluoroquinolones could also be considered but are associated with a higher rate of adverse events. Doxycycline and fluoroquinolones should be used with more caution in children.

There are higher rates of S. pneumoniae and Hemophilus influenzae resistance to second-generation cephalosporins, trimethoprim/sulfamethoxazole, and macrolides.

Evidence has also shown that antibiotic therapy does not necessarily shorten symptom duration or complication rates in adults. Many cases of ABRS may also spontaneously resolve within two weeks. Clinicians can offer symptomatic treatments; however, clear evidence is lacking overall.

Nasal steroids and nasal saline irrigation are the most common recommendations in guidelines. Intranasal steroids may help by reducing mucosal swelling, which can help relieve the obstruction. A small number of trials indicated that higher doses of intranasal steroids could help improve the time to symptom resolution at 2 to 3 weeks. Nasal saline irrigation can also help reduce obstruction.

Antihistamines are not a recommendation unless there is a clear allergic component as they potentially thicken nasal secretions.

Suspicion for the invasive form of acute fungal rhino-sinusitis should prompt urgent evaluation and referral to otolaryngology, neurosurgery, and/or ophthalmology for biopsy. These patients will require combined medical and surgical management (debridement) if this diagnosis is confirmed on histology.

Acute bacterial rhino-sinusitis is most commonly viral. The large majority of cases will either resolve spontaneously or can be effectively treated with antibiotics. Invasive fungal rhinosinusitis is a rare, serious form of the infection that can occur in immunocompromised patients. It is associated with a high morbidity and mortality rate.


Referral to an otolaryngologist / ENT Surgeon is rarely needed since most cases are viral and will resolve spontaneously.

Acute uncomplicated bacterial sinusitis can be easily treated by primary care physicians with antibiotics. However, if a complication is suspected, prompt referral to an otolaryngologist is required to avoid the potentially catastrophic effects of intracranial and orbital extension.

Reasons for urgent referral include:

  • Mental status changes

  • Cranial nerve abnormalities

  • Pain with extraocular movements

  • Periorbital edema

  • Severe or refractory symptoms in an immunocompromised patient

Routine referral to an otolaryngologist may also be done for any intractable or refractory case of rhino-sinusitis to provide further evaluation.


Image of a balloon sinuplasty catheter courtesy from Easmed

If conservative management fails or does not respond adequately to "maximal. medical treatment", there are other Treatment options available :

  1. Sinus Wash out

  2. Balloon Sinuplasty

  3. Endoscopic Sinus Surgery

Do contact us if you would like more information on such sino-nasal surgeries; or to book a consultation to see us at Euan's ENT Surgery & Clinic to make an appointment or call our clinic number 6694 4282.

Acute bacterial rhino-sinusitis is most commonly viral.

The large majority of cases will either resolve spontaneously or can be effectively treated with antibiotics. Invasive fungal rhino-sinusitis is a rare, serious form of the infection that can occur in immunocompromised patients. It is associated with a high morbidity and mortality rate.ALWAYS look out for such patients and bring them in EARLY for assessment.

I hope this BLOG POST has been useful to you. Have a very happy weekend 😊


1.Aring AM, Chan MM. Current Concepts in Adult Acute Rhinosinusitis. Am Fam Physician. 2016 Jul 15;94(2):97-105. [PubMed]

2.DeMuri G, Wald ER. Acute bacterial sinusitis in children. Pediatr Rev. 2013 Oct;34(10):429-37; quiz 437. [PubMed]

3.Rosenfeld RM, Piccirillo JF, Chandrasekhar SS, Brook I, Ashok Kumar K, Kramper M, Orlandi RR, Palmer JN, Patel ZM, Peters A, Walsh SA, Corrigan MD. Clinical practice guideline (update): adult sinusitis. Otolaryngol Head Neck Surg. 2015 Apr;152(2 Suppl):S1-S39. [PubMed]

4.Chow AW, Benninger MS, Brook I, Brozek JL, Goldstein EJ, Hicks LA, Pankey GA, Seleznick M, Volturo G, Wald ER, File TM., Infectious Diseases Society of America. IDSA clinical practice guideline for acute bacterial rhinosinusitis in children and adults. Clin Infect Dis. 2012 Apr;54(8):e72-e112. [PubMed]

5.Berger G, Kattan A, Bernheim J, Ophir D, Finkelstein Y. Acute sinusitis: a histopathological and immunohistochemical study. Laryngoscope. 2000 Dec;110(12):2089-94. [PubMed]

6.Wald ER, Applegate KE, Bordley C, Darrow DH, Glode MP, Marcy SM, Nelson CE, Rosenfeld RM, Shaikh N, Smith MJ, Williams PV, Weinberg ST., American Academy of Pediatrics. Clinical practice guideline for the diagnosis and management of acute bacterial sinusitis in children aged 1 to 18 years. Pediatrics. 2013 Jul;132(1):e262-80. [PubMed]

7.Rosenfeld RM. CLINICAL PRACTICE. Acute Sinusitis in Adults. N Engl J Med. 2016 Sep 08;375(10):962-70. [PubMed]

8.Brook I. Acute sinusitis in children. Pediatr Clin North Am. 2013 Apr;60(2):409-24. [PubMed]

9.Boisselle C, Rowland K. PURLs: Rethinking antibiotics for sinusitis: again. J Fam Pract. 2012 Oct;61(10):610-2. [PMC free article] [PubMed]

10.Zalmanovici Trestioreanu A, Yaphe J. Intranasal steroids for acute sinusitis. Cochrane Database Syst Rev. 2013 Dec 02;2013(12):CD005149. [PMC free article] [PubMed]

11.Dwyhalo KM, Donald C, Mendez A, Hoxworth J. Managing acute invasive fungal sinusitis. JAAPA. 2016 Jan;29(1):48-53. [PubMed]

12.Knipping S, Hirt J, Hirt R. [Management of Orbital Complications]. Laryngorhinootologie. 2015 Dec;94(12):819-26. [PubMed]

13.Schubert MS. Allergic fungal sinusitis: pathophysiology, diagnosis and management. Med Mycol. 2009;47 Suppl 1:S324-30. [PubMed]


Dr Euan Drawing.jpeg




bottom of page