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Acute sinusitis in children can be defined as the acute inflammation of the paranasal sinus mucosa or nasal passages with a duration of < 4 weeks. This inflammatory condition can be caused by viral, bacterial, or fungal infections. Non-infectious etiologies of acute sinusitis can be attributed to allergens or irritants.
Epidemiology of Sinusitis
Upper respiratory tract infections are common in children with an estimated incidence of six episodes per patient-year. Approximately, 8% of these upper respiratory tract infection episodes are complicated by episodes of rhinosinusitis in children between 6 and 35 months of age.
There are no differences in the incidence of rhinosinusitis among boys and girls; however, the condition has become more common in both sexes over the past decade.
Children with congenital genetic disorders that impair mucosal ciliary movement or those with an impaired secretory immune response are predisposed to recurrent episodes of rhinosinusitis.
Etiology and Pathophysiology of Sinusitis
The most common etiology of rhinosinusitis is viral in origin and secondary bacterial infections of the sinuses are common. Streptococcus pneumoniae, Moraxella catarrhalis, Staphylococcus aureus, and non-typeable Haemophilus influenzae are the most commonly identified etiologies of bacterial rhinosinusitis.
For bacteria to colonize the nasal and paranasal sinuses and cause symptoms, certain pathological changes must first occur within the nasal and paranasal passages.
The most important pathophysiological change encountered is the obstruction of the sinus drainage pathways, and otitis media is a common cause bringing about this change in children. The normal metachronous movement of mucous towards the natural ostia of the sinuses is disrupted by mucosal inflammation.
Additionally, children with recurrent bacterial rhinosinusitis usually show some evidence of ciliary impairment and alteration in the quantity or quality of mucus. The latter can be attributed to asthma and other allergic conditions.
Viral upper respiratory tract infections can also alter the composition and quantity of the mucus within nasal and paranasal sinuses, which can put the child at an increased risk of acquiring a secondary bacterial infection.
Clinical Presentation of Sinusitis
When a child presents with symptoms and signs suggestive of an upper respiratory tract infection, attention should be paid to the severity of the symptoms and the possibility of rhinosinusitis.
Common cold presents with a runny nose with mucous discharge and improves within 10 days; however, it may be accompanied by fever that may last up to two days. The pattern of illness in acute bacterial sinusitis can be categorized as follows:
- Persistent sinusitis (common) presents with nasal discharge (any quality), daytime cough (which may worsen at night), or both, for at least 10 days without signs of improvement.
- Severe sinusitis presents with concurrent fever with a purulent nasal mucous discharge that is thick, colored, or cloudy for at least three consecutive days and is accompanied by severe facial pain and headache.
- Worsening sinusitis begins with a viral cold but later worsens after a bacterial infection; there is a new onset of nasal discharge, daytime cough, or high-grade fever after initial improvement.
Differentiating viral and bacterial sinusitis
Rhinosinusitis is a presenting feature in almost all children with viral upper respiratory tract infections; therefore, it is important to differentiate bacterial from viral sinusitis. This distinction is important because viral rhinosinusitis resolves spontaneously, while the bacterial variant in children requires specific antimicrobial therapy.
Diagnosis of acute bacterial sinusitis
The diagnosis of acute bacterial sinusitis is made when the child exhibits two major criteria, or one major and two or more minor criteria from the clinical diagnostic criteria of bacterial sinusitis.
Major criteria include the following:
- Facial pain or congestion
- Nasal congestion or discharge, which can be purulent
- Loss of the sense of smell
- Purulent discharge on intranasal examination
Minor criteria include the following:
- Dental pain
- Ear pain
If acute sinusitis is suspected, the treating physician should look for clues that point to a possible bacterial than viral etiology. The most crucial differences between bacterial and viral acute sinusitis, in favor of the former, are respiratory symptoms lasting more than ten days, purulent nasal discharge and a high-grade fever, and worsening of symptoms after an initial temporary improvement.
Diagnostic Workup for Sinusitis
Proper history taking and a physical examination are required in children who present with upper respiratory tract infection symptoms, to differentiate between viral and bacterial etiologies. Patients with suspected acute bacterial sinusitis should be suggested advanced confirmatory tests, if possible, before starting antibiotic therapy.
Laboratory investigations are usually not helpful in children with acute sinusitis as leukocytosis is rare. Children with severe acute bacterial rhinosinusitis may exhibit leukocytosis and neutrophilia. The following investigations may be considered:
- Culture and sensitivity test: The best diagnostic test to confirm the diagnosis of bacterial sinusitis in children is a culture and sensitivity test from the paranasal sinus cavity. The presence of more than 104 colony-forming units/mL in the cultured sample is indicative of bacterial sinusitis in children.
- Sinus aspiration is rarely used in children because it is invasive, painful, and impractical.
- Endoscopy-guided middle meatal aspirates can be cultured to confirm the diagnosis of acute bacterial rhinosinusitis; however, their validity has not been tested in children.
- Imaging studies can provide more clues towards the diagnosis of acute sinusitis in children, but they have several drawbacks. First, computed tomography (CT) studies might show sinus abnormality even in healthy children. Second, skull X-rays and CT scans cannot differentiate between viral and bacterial sinusitis. Third, imaging studies in children with viral upper respiratory tract infections can show sinus abnormalities in more than 80% of the cases without any clinical symptoms and signs suggestive of sinusitis.
Because of these reasons, imaging studies should be reserved only for complicated and recurrent cases.
Imaging studies are more useful in excluding the diagnosis of acute sinusitis rather than confirming it. A negative CT scan is reliable in excluding acute sinusitis as the underlying cause of a headache or facial pain.
Magnetic resonance imaging studies of the brain are useful in excluding complications of acute bacterial sinusitis such as brain abscess and cerebrovascular venous thrombosis.
Treatment of Sinusitis
Once the diagnosis of acute bacterial rhinosinusitis has been established, empirical antibiotic therapy should be started. Additionally, symptomatic treatment of nasal and sinus congestion is indicated to decrease the severity and duration of symptoms.
Therapy with antibiotics
Amoxicillin as first-line treatment
The antibiotic of choice for acute bacterial sinusitis in children is amoxicillin-clavulanate. The dose is usually dependent on the severity of the infection. Children with non-severe sinusitis usually receive a standard dose of 45 mg/kg/d orally, three times a day. High-dose amoxicillin-clavulanate is defined as an oral dose of 90 mg/kg/d twice a day and should be reserved for children with severe bacterial sinusitis.
Ceftriaxone (a substitute for oral antibiotics): Children who are unable to tolerate oral medication should be given a single dose of 50 mg/kg/d ceftriaxone intravenously or intramuscularly.
Patients with penicillin allergy
If sinusitis caused by penicillin-resistant S. pneumoniae is suspected, children exhibiting type-1 hypersensitivity to penicillin derivatives can be treated with a combination of clindamycin (or linezolid) and cefixime. Linezolid is effective against S. pneumoniae, but lacks activity against H. influenzae and M. catarrhalis. Levofloxacin, which has a high level of activity against both S. pneumoniae and H. influenzae, may be prescribed instead of amoxicillin-clavulanate and linezolid. Children with a delayed hypersensitivity reaction to penicillin can also receive a combination of cefixime and clindamycin.
In contrast to adults, short-term antibiotic therapy is not recommended in children. Instead, empirical antibiotic therapy ranging from ten days up to two weeks is recommended. Children usually show significant improvement in symptoms within five days of initiation of antibiotic therapy.
Adjuvant therapy for acute sinusitis includes intranasal corticosteroids, saline nasal irrigation or lavage, topical or oral decongestants, mucolytics, and topical or oral antihistamines.
Intranasal corticosteroids have shown objective clinical improvement in children with acute bacterial sinusitis and are recommended as an adjunctive therapy.
Saline nasal irrigation or lavage (not saline nasal spray) has been used to remove debris from the nasal cavity and temporarily reduce tissue edema to promote drainage from the sinuses.
Topical or oral decongestants, mucolytics, and topical or oral antihistamines are not generally recommended for acute bacterial sinusitis in children. Antihistamine therapy is useful in reducing typical allergic symptoms in children with atopy who also have acute sinusitis. Adequate hydration and mucolytic agents might be useful in children with acute bacterial rhinosinusitis as they facilitate sinus drainage and help achieve symptomatic relief.
Children who fail to respond to medical therapy or those with frequent recurrences should be indicated surgery aimed at the drainage of sinuses. Surgical approaches include the following:
- Functional endoscopic sinus surgery
- Removal of the uncinate process, anterior ethmoidectomy, and maxillary antrostomy (most common)
- Balloon sinuplasty
Functional endoscopic sinus surgery is currently the best therapeutic option, which has shown success in about 75% of patients with complicated, persistent bacterial sinusitis.