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Upper respiratory tract infections (URIs) are the single most common disorders seen by primary care physicians. Children usually have six to eight URIs annually.1 Symptoms include cough, nasal obstruction, rhinorrhea, low-grade fever, and sore throat. Most conditions resolve with conservative management.² It has been estimated that 5 to 10% of URIs are complicated by rhinosinusitis.³

Chronic rhinosinusitis is becoming an increasingly common diagnosis in children and can be a frustrating problem.⁴ Several factors may contribute to this trend. More young children are attending day care centers, increasing the transmission of URIs. Environmental pollutants and allergens predispose children to rhinosinusitis. There is also heightened awareness and improved ability to diagnose sinus disease with recent advances in imaging technology and fiberoptic instrumentation.²

Definition and Clinical Presentation

The spectrum of pediatric nasal and paranasal infections ranges from acute viral rhinitis to chronic rhinosinusitis. The viral URI is the most common infection, and its incidence peaks during early childhood. The usual pathogens include rhinovirus, adenovirus, coronavirus, influenza virus, parainfluenza virus, respiratory syncytial virus, and coxsackievirus. During the winter months, an increased incidence of viral URIs is common, but the peak month, September, coincides with the beginning of school. Clinically, patients experience a sudden onset of nasal congestion with clear or mucoid rhinorrhea, usually accompanied by fever. Symptoms resolve within 10 to 14 days with symptomatic treatment.⁵

Acute rhinosinusitis is defined by the persistence of URI symptoms for more than 10 days and less than 6 weeks, with fewer than four episodes a year. Typically, the symptoms are more severe than with those of a URI. Treatment requires antibiotics, and the condition resolves without permanent mucosal changes.⁶

In younger children the clinical presentation is less obvious, and only older children and adolescents present with adultlike symptoms. Symptoms often associated with acute adult rhinosinusitis, such as fever and purulent nasal discharge, are often absent in young children.⁴ Rhinorrhea and daytime cough are present in 80% of children with acute rhinosinusitis. Acute rhinosinusitis is the second most common cause of cough in children. The cough is present during the day and may worsen at night.⁶ Fatigue, behavioral changes, and increased irritability are also frequently noted. In infants, irritability may be the only presenting symptom.⁷ Less frequently, acute rhinosinusitis may manifest as a severe URI with a fever greater than 39°C, facial pain, periorbital swelling, and copious, purulent rhinorrhea. Other symptoms, such as fetid breath and dental pain, may also be present.⁸

Recurrent acute rhinosinusitis is defined as more than four episodes of acute rhinosinusitis a year. These episodes resolve with medical treatment. Between episodes, there is an absence of the signs and symptoms of acute rhinosinusitis.⁹

Subacute rhinosinusitis is defined by the persistence of symptoms lasting longer than 6 weeks but less than 3 months. It represents a continuum between acute and chronic rhinosinusitis. The nasal discharge may be of any quality, and low-grade fevers may also be present.⁸

Chronic rhinosinusitis has symptoms persisting longer than 12 weeks. In contrast to acute rhinosinusitis, radiographic evidence of mucosal thickening or opacification of the paranasal sinuses is present even after appropriate medical management.6

Differential Diagnosis

Rhinorrhea and nasal congestion in children may be a result of multiple causes, including foreign bodies, enlarged and/or infected adenoids, allergic rhinitis, choanal atresia, hypothyroidism, congenital syphilis, and masses.¹⁰ Other causes of chronic rhinitis include rhinitis medimentosa and vasomotor rhinitis.¹¹ Rhinorrhea in neonates is frequently misdiagnosed as rhinosinusitis. This condition is more appropriately named rhinitis of infancy.¹²

Chronic cough is caused most frequently by reactive airway disease. Other etiologies include gastroesophageal reflux, cystic fibrosis, pertussis, mycoplasma bronchitis, and tuberculosis.⁸

Developmental Anatomy

The growth of the individual sinuses varies with age and affects the clinical presentation of paranasal sinus disease. An understanding of the developmental anatomy of the nose and paranasal sinuses is important for the management of pediatric rhinosinusitis.

In utero, the maxillary sinuses develop early in the second trimester as lateral buds within the ethmoid infundibulum at the posterior aspect of the middle meatus. The anterior and posterior ethmoid sinuses originate during the third and fourth months of gestation, respectively. An anterosuperior ethmoid infundibulum expansion becomes the fetal frontal recess. The development of the sphenoid sinuses is unique, as they do not originate from the lateral nasal wall. They begin as recesses within the posterior aspect of the cartilaginous nasal capsule around the fourth month.¹³

In the newborn, the paranasal sinuses are small and contribute very little to the nasal-paranasal volume. The turbinates are extremely bulky, and their respective meatus are excluded from the functional airway. The ethmoid sinuses and bulla, the uncinate process, and the hiatus semilunaris are already well developed. The maxillary sinus is a shallow sac. The frontal sinus presents as a small cell in the anterosuperior portion of the infundibulum. The sphenoid sinus is a blind mucosal sac in the sphenoethmoid recess.¹⁴

Wolf et al¹⁴ reviewed the growth of the paranasal sinuses from birth to age 12. In children from age 1 to 4 years, the ethmoid sinuses expand in all directions. They are more developed than the other sinuses and can be the origin of orbital complications. The maxillary sinus enlarges laterally to the infraorbital canal and inferiorly to the level of the attachment of the inferior turbinate. The frontal sinus expands slowly and begins pneumatizing the frontal bone. The sphenoid sinus is 4 to 8 mm in diameter at age 4.

From 4 to 8 years, the development of the paranasal sinuses slows, but they continue to expand in all directions. The ethmoid air cells enlarge more slowly than the frontal and maxillary sinuses. The frontal sinus expands laterally into the frontal bone. The maxillary sinus floor descends to the level of the middle of the inferior meatus, and the lateral wall expands past the infraorbital canal. At this time the tooth buds of the secondary teeth are at greater risk during surgery involving the maxilla.¹⁴

Between 8 to 12 years, the growth of the paranasal sinuses accelerates, and pneumatization progresses rapidly. The maxillary sinus continues to grow, especially after the secondary dentition has erupted. The maxillary sinus floor reaches the level of the nasal cavity floor. The ethmoid sinuses are almost completely pneumatized. The sphenoid sinuses have reached their permanent size and position but will continue to undergo alterations in shape. The frontal sinuses become clinically significant in size between age 8 to 10 years. By 12 years, the nasal cavity and paranasal sinuses have nearly completed their development.¹⁴

The adult paranasal anatomy is reached during the second decade of life. The ethmoid sinuses attain their final form between 12 and 14 years. By 14 to 16 years, the sphenoid sinus has completed its development. The maxillary sinus continues to grow until 14 to 18 years. The frontal sinus usually reaches its final size by age 15, but in some individuals growth may continue until age 21.¹³

Developmental variations exist. The frontal sinuses are present bilaterally in 80% of patients but are often asymmetric. Unilateral frontal sinus hypoplasia is reported in 3.0 to 7.4% of patients and bilateral agenesis in 1 to 4.8%. The sphenoid sinus has wide variation in shape, size, symmetry, intersinus septum position, and wall thickness. The sphenoid sinus may also pneumatize areas outside the body of the sphenoid bone. Careful inspection of the sphenoid anatomy is recommended prior to any surgery. There is a 1.0 to 1.5% incidence of bilateral agenesis of the sphenoid sinuses.¹³

Pathogenesis and Predisposing Factors

Normal paranasal physiology requires patency of the ostia, normal mucociliary clearance, and normal secretions. When any one of these changes, ostial obstruction, retention of secretions, and infection can occur.¹⁵ Factors that predispose to changes can be divided into systemic and local conditions. Systemic factors include URIs, allergies, immunodeficiencies, mucociliary dysfunction, and diseases, such as cystic fibrosis. Local factors include structural abnormalities, adenoid hypertrophy and infection, trauma, and irritants.16

Viral URIs are the most common predisposing factor of rhinosinusitis. Rhinosinusitis develops in 10% of URIs. The infection causes mucosal edema and impairment of ciliary function, causing both ostial obstruction and mucous stasis.⁶

Mucosal swelling is commonly caused by allergy. Fifty-eight to 81% of all patients treated for chronic rhinosinusitis have a positive allergy evaluation.¹⁷ Children should be evaluated for the signs and symptoms of allergy, such as itchy and watery eyes, itchy palate, sneezing, clear rhinorrhea, allergic shiners, allergic salute, and mucosal hyperemia. An allergy evaluation should be considered in any child with significant sinus disease. Allergies to food, particularly milk proteins, are the most common allergies in young children.¹⁸

Children have a physiologic delay in the development of their immune system. A 2-year-old child’s immune system is ~50% of the adult level and does not reach adult level until age 10. This diminished immune competence increases the potential for infection. Pathologic abnormalities in the immune system also occur. Infants may have hypogammaglobulinemia, and young children more commonly have Ig subclass deficiencies. The most common immunodeficiencies in children with chronic rhinosinusitis are IgG3 deficiency and poor humoral antibody response to pneumococcal antigen (Ag) 7. Quantitative Ig measurements should be considered in the evaluation of children with chronic rhinosinusitis.^19,20

Ciliary dysfunction leads to stasis of secretions within the paranasal sinuses, providing an environment for infection. Structural abnormalities affect ciliary function in disorders such as Kartagener’s or immotile cilia syndrome. Ciliary function may be affected temporarily by viral infections and exposure to irritants and pollutants.¹⁵ Assessing ciliary function in vivo with a saccharin clearance test or examining the ultrastructure of the cilia by electron microscopy can be used to diagnose ciliary dyskinesis.^21,22

Cystic fibrosis is an autosomal-recessive disorder with widespread exocrine gland dysfunction. Abnormalities in the mucus prevent the movement of secretions.¹⁵ Bacteria, especially Pseudomonas, and fungi, can colonize these inspissated secretions.²³ Ten to 30% of patients with cystic fibrosis have nasal polyps, and 70% of children with polyps have cystic fibrosis.^24,25 A sweat test or genetic testing should be performed on any child with nasal polyps.^24,26

Although asthma does not cause rhinosinusitis, it has been associated with chronic rhinosinusitis. Parsons and Phillips⁷ reported that 46% of children with rhinosinusitis had asthma. In older children and adolescents, asthma is associated with nasal polyps.

Abnormalities may block the sinus ostia and predispose to disease. Some conditions include foreign bodies, septal deviations, polyps, neoplasms, congenital or craniofacial anomalies, meningoceles, and encephaloceles.⁴ Imaging of any intranasal mass should be performed prior to a biopsy to determine its origin and extent.

Adenoid hyperplasia and infections may predispose a child to rhinosinusitis. Large or infected adenoids may produce nasal obstruction and symptoms of rhinosinusitis.²⁶ The adenoids may serve as a reservoir for pathogenic bacteria.²⁷

Other local predisposing factors include irritants such as air pollution and tobacco smoke.¹⁵ Abuse of topical decongestants can cause mucosal swelling and rhinorrhea. This condition is termed rhinitis medimentosa.⁴

Diagnosis

History

The diagnosis of pediatric rhinosinusitis may be challenging. Although a thorough history is important, most children are poor historians and frequently cannot accurately describe their symptoms. Children under 5 years of age are less verbal, and their symptoms are usually nonspecific. Older children can usually be questioned more successfully. Information from the parents and the referring physicians is invaluable.²⁸

Questions regarding cough and rhinorrhea, the most common symptoms of pediatric rhinosinusitis, must be asked. The history should also include details pertaining to the presence, duration, and quality of other symptoms, such as fever, nasal obstruction, headaches, facial pressure and pain, behavioral changes and irritability, fetid breath, otalgia, and periorbital edema. Precipitating events should be investigated. A history of day care, smoke exposure, and siblings’ health should be obtained.

Physical Examination

The physical exam of a child can be difficult. During the evaluation, observations concerning cough, hyponasality, allergic salute or shiners, rhinorrhea, and other signs should be noted. Younger children usually tolerate only limited anterior rhinoscopy with an otoscope. Older children may allow the use of a headlight and nasal speculum or a fiberoptic nasopharyngoscope, which can also inspect the nasopharynx and adenoids. Adolescents may tolerate rigid endoscopy after being topicalized with a decongestant and local anesthetic.

During the examination of the nasal cavity, purulence, crusting, and mucus should be noted and characterized. The mucosa, turbinates, meatus, and septum should be inspected.26 Rhinosinusitis is confirmed by the presence of mucopurulence in the middle meatus.⁴ Purulent post-nasal drainage and enlarged or inflamed lymphoid tissue in the oropharynx are common but nondiagnostic signs.¹⁵ Unilateral purulent rhinorrhea may suggest a mass, foreign body, or unilateral choanal atresia.⁴

Cultures of nasal secretions may be warranted if symptoms persist even with conventional medical management or if the symptoms return within 1 week after cessation of antibiotics. Cultures of secretions from the middle meatus or ethmoid bulla provide the best bacterial yields in chronic rhinosinusitis.²⁹ In children, the variable size and position of the developing maxillary sinus make a sinus puncture unsafe.¹⁴

Transillumination has little value in young children. The increased thickness of the bone and soft tissues limits its effectiveness. It may be useful in the adolescent whose paranasal sinuses are nearly completely developed.¹⁶

Imaging

Plain lateral neck radiographs can help in diagnosing enlarged adenoid tissue.¹⁵ Plain sinus films are readily available and inexpensive but are not specific or sensitive, especially for chronic disease. They can help diagnose acute rhinosinusitis and are most accurate with well-developed maxillary and frontal sinuses.³⁰

McAlister et al³¹ and Lazar et al³² compared computed tomography and plain films. Plain films under- and overestimated the degree of chronic disease and were not a reliable screen for chronic rhinosinusitis. What appeared to be mucosal thickening on plain films was not reliably confirmed by CT and should not be used as diagnostic criteria for rhinosinusitis. For unilateral, recurrent, or chronic rhinosinusitis, CT is the imaging study of choice. Axial CT is excellent for demonstrating the sphenoid sinus and the surrounding anatomy. Coronal CT is useful in demonstrating all the paranasal bony anatomy and the relationship of relevant structures.

The timing of the CT is critical. The child should be maximally medically treated prior to the study. This usually implies treatment with at least 3 to 4 weeks of appropriate oral antibiotics, nasal saline, and steroid sprays. CT should be performed in children who remain symptomatic after medical therapy and who are likely to undergo surgery.

The CT findings should be correlated with clinical findings. Up to 45% of asymptomatic patients may have incidental maxillary or ethmoid opacification. In addition, patients with resolving URIs may have persistent CT findings for up to 2 weeks after resolution of the infection.³³

Magnetic resonance imaging is useful for demonstrating soft tissue structures. It can help evaluate fungal sinusitis and extension of sinus tumors.¹⁵ Compared with CT, MRI tends to overemphasize mucosal disease, leading to a higher false-positive rate.³⁴

Microbiology

Acute and subacute pediatric rhinosinusitis pathogens are similar to those reported for otitis media and acute adult rhinosinusitis.^35–37 The most common pathogens are Streptococcus pneumoniae (25–30%) , Moraxella catarrhalis (15–20%), and Haemophilus influenzae (15–20%). Anaerobes were isolated from only ~2 to 5% of aspirates. Adenovirus, parainfluenza, and several other viruses were cultured in 3 to 15%.

Chronic pediatric rhinosinusitis is considered a polymicrobial infection. In addition to the pathogens isolated in acute rhinosinusitis, Staphylococcus aureus and anaerobes, particularly Bacteroides species, have been cultured.^6,38 Muntz and Lusk²⁹ described cultures from 204 ethmoid bulla and found a predominance of α-hemolytic Streptococcus and Staphylococcus aureus, with a high incidence of β-lactamase producing organisms and anaerobes in only 7% of cases. Brook,³⁹ however, reported a 92% incidence of anaerobic infection.

Systemic conditions may alter the pathogenic flora. Patients with cystic fibrosis have a higher incidence of Pseudomonas infections. Immunocompromised patients may have fungal infections with Aspergillus species, Rhizopus species, and Fusarium species.⁴⁰ Invasive fungal rhinosinusitis must be considered in severely immunocompromised children.

Medical Treatment

Acute pediatric rhinosinusitis resolves spontaneously in 40% of cases and therefore should be treated conservatively.⁴¹ The goals of therapy are the control of infection, reversal of mucosal pathology and tissue edema, facilitation of sinus drainage, and reestablishment and maintenance of ostial patency.⁴²

Children with chronic rhinosinusitis frequently have concurrent allergy, lower airway disease, and systemic diseases, requiring multiple medications and therapeutic interventions. It is essential that these children be treated in consultation with pulmonologists, allergists, and immunologists.⁴²

The mainstays of medical treatment of pediatric rhinosinusitis are antibiotics and steroids. Adjunctive medical treatment such as mucolytic agents, nasal irrigations, anticholinergic agents, antihistamines, and mast-cell stabilizers may also be instituted. Other therapeutic interventions such as immunotherapy or Ig replacement therapy may be required.42

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