Acute sinusitis

Acute sinusitis is an inflammation of one or more of the sinus cavities, caused by an infection or allergy.
Most acute sinus infections are viral and resolve spontaneously in less than 10 days. Treatment is symptomatic.
Acute bacterial sinusitis may be a primary infection, a complication of viral sinusitis or of dental origin. The principal causative organisms are Streptococcus pneumoniaeHaemophilus influenzae and Moraxella catarrhalis.
It is essential to distinguish between bacterial sinusitis and common rhinopharyngitis (see Rhinitis and rhinopharyngitis). Antibiotic therapy is required in case of bacterial sinusitis only.
Without treatment, severe sinusitis in children may cause serious complications due to the spread of infection to the neighbouring bony structures, orbits or the meninges.

Clinical features

Sinusitis in adults

– Purulent unilateral or bilateral discharge, nasal obstruction
– Facial unilateral or bilateral pain that increases when bending over; painful pressure in maxillary area or behind the forehead.
– Fever is usually mild or absent.

Sinusitis is likely if symptoms persist for longer than 10 to 14 days or worsen after 5 to 7 days or are severe (severe pain, high fever, deterioration of the general condition).

Sinusitis in children

– Same symptoms; in addition, irritability or lethargy or cough or vomiting may be present.
– In the event of severe infection: deterioration of the general condition, fever over 39 °C, periorbital or facial oedema.


Symptomatic treatment

– Fever and pain (Chapter 1).
– Clear the nose with 0.9% sodium chloride1 .


– In adults:

Antibiotherapy is indicated if the patient meets the criteria of duration or severity of symptoms. Oral amoxicillin is the first-line treatment.
If the diagnosis is uncertain (moderate symptoms < 10 days) and the patient can be reexamined in the next few days, start with a symptomatic treatment, as for rhinopharyngitis or viral sinusitis.

– In children:

Antibiotic therapy is indicated if the child has severe symptoms or mild symptoms associated with risk factors (e.g. immunosuppression, sickle cell disease, asthma). Oral amoxicillin is the first-line treatment.
amoxicillin PO for 7 to 10 days:
Children: 30 mg/kg 3 times daily (max. 3 g daily)
Adults: 1 g 3 times daily

In the event of failure to respond within 48 hours of therapy:
amoxicillin/clavulanic acid PO for 7 to 10 days. Use formulations in a ratio of 8:1 or 7:1 exclusively. The dose is expressed in amoxicillin:
Children < 40 kg: 25 mg/kg 2 times daily
Children ≥ 40 kg and adults:
Ratio 8:1: 2000 mg daily (2 tablets of 500/62.5 mg 2 times daily)
Ratio 7:1: 1750 mg daily (1 tablet of 875/125 mg 2 times daily)

In penicillin-allergic patients:
erythromycin PO for 7 to 10 days:
Children: 30 to 50 mg/kg daily2
Adults: 1 g 2 to 3 times daily

– In infants with ethmoiditis, see Periorbital and orbital cellulitis (Chapter 5).

Other treatments

– For sinusitis secondary to dental infection: dental extraction while under antibiotic treatment.
– In the event of ophthalmologic complications (ophthalmoplegia, mydriasis, reduced visual acuity, corneal anesthesia), refer for surgical drainage.

Ref Notes
1 For a child: place him on his back, head turned to the side, and instil 0.9% sodium chloride into each nostril.
2 For dosage according to age or weight, see erythromycin in the guide Essential drugs, MSF.