History

Purulent sinusitis and its relationship to orbital inflammation have been known for more than 2000 years. Highmore, a 17th-century English physician and anatomist, is given credit for the separation of dental and antral disease. Hunter indicated the importance of surgical drainage in purulent sinusitis and suggested perforating the partition between the maxillary antrum and the nose. During the first half of the 20th century, sinusitis was responsible for considerable morbidity and mortality, and surgical care of sinusitis frequently was lifesaving. Since the advent of antibiotics, sinusitis has had a lower medical profile. Interest in this topic has increased, however. Some factors involved in this increased interest include the advent of the newer surgical techniques of functional endoscopic sinus surgery that yield comparable results to sinus puncture and aspiration, which now have been applied to children; improved diagnostic imaging studies, especially thin-cut computed tomography (CT) imaging; and the greater social importance of upper respiratory tract infections for parents who must be absent from work to seek treatment for their children.

Anatomy

All the paranasal sinuses develop as outpouchings of the nasal cavity. Three shelflike structures—the inferior, middle, and superior turbinates—are on the lateral nasal wall. The superior turbinate is not well developed in the first year of life. Beneath each turbinate is the corresponding meatus into which various drainage pathways open. Specifically, the nasolacrimal duct drains tears into the inferior meatus; the frontal, maxillary, and anterior ethmoidal sinuses drain into the middle meatus; and the sphenoidal and posterior ethmoidal cells open high in the nasal vault in the proximity of the superior meatus.

The maxillary sinuses develop early in the second trimester of fetal life as lateral outpouchings in the posterior aspect of the middle meatus. They are present at birth, with floors being barely below the attachment of the inferior turbinates. They expand rapidly by the time the child is 4 years of age. Ultimately, at full size, the lateral borders of the maxillary sinuses reach the lateral orbital rims. The position of the floors of the sinuses is determined by the eruption of the dentition. The ostia of the maxillary sinuses are located high on the medial walls of the sinuses, which impedes gravitational drainage of secretions; ciliary activity is required to move secretions from the body of the maxillary sinuses through the ostia into the nose.

The ethmoidal sinuses develop in the fourth month of gestation and are present at birth. They are not a single large cavity but a grouping of cells, three to 15 in number, each with its own opening or ostium. They have a honeycombed radiographic appearance and are small anteriorly and large posteriorly. The walls of the ethmoidal labyrinth, especially the lateral walls bordering on the orbits (and forming its medial walls), are thin and referred to as the lamina papyracea.

Development of the frontal sinuses is variable. In adults, 80% have bilateral frontal sinuses, 1% to 4% have agenesis of the frontal sinuses, and the remainder have unilateral hypoplasia. The position of the frontal sinuses is supraorbital after the child reaches 4 years of age, but they are not distinguished radiographically from the ethmoidal sinuses until the child is 6 to 8 years old. The frontal sinuses do not reach adult size for another 8 to 10 years.

The onset of development of the sphenoidal sinuses occurs during the child’s first 2 years of life, but they remain rudimentary until the child is approximately 6 years of age. They have reached their permanent size, although not their permanent shape, by the time the child is 12 years old.

Although the full development of the sinuses may take 20 years, by the time the child is 12 years old the nasal cavity and the paranasal sinuses have nearly completed their development and have reached adult proportions. Sinus disease in postpubertal adolescents is similar to that in adults.

The mucosal lining of all the paranasal sinuses is composed of ciliated columnar epithelium and goblet cells. It is continuous and similar to the lining of the nasal cavity except that the mucosa in the nose is thicker and contains more glands. The epithelium of all the paranasal sinuses and nasal cavity is covered in part by a blanket of mucus.

Pathophysiology

The pathogenesis of sinus infection undoubtedly is similar to that of otitis media. The middle ear, with its extension, the eustachian tube, and the paranasal sinuses normally are sterile, but their contiguous areas (nasopharynx and nose) have a dynamic microbial flora. Under normal conditions, ciliary function with mucus flow can be expected to keep the sinuses clear of pathogens. The cilia within the sinuses propel the mucus toward their respective ostia and, from there, nasociliary action moves the mucus blanket posteriorly toward the pharynx. Insults that damage the ciliary epithelium and affect the morphology, number, and function of cilia and insults that alter the production or viscosity of the mucus blanket lead to obstruction of the flow of mucus, however, which allows the inoculation of numerous microorganisms into the sinuses that can lead to infection. In a study in adults in whom sneezing, coughing, and nose blowing were stimulated or initiated voluntarily, intranasal pressures were measured, and the deposition of contrast medium (which before the initiation of the event had been inoculated into the nasopharynx) was determined by CT. Results of this study showed that nose blowing introduced viscous fluid into the maxillary sinuses, whereas coughing or sneezing did not generate enough pressure to propel fluid into the sinuses. When instituted, sinus infection is complicated further by inflammatory obstruction of the ostium leading to the nose.

The most important factor leading to purulent sinus infection in children and in adults is upper respiratory tract viral infection. Wald and colleagues in a large prospective study involving children younger than 3 years of age showed a doubling of the rate of sinusitis (defined as upper respiratory tract symptoms persisting >15 days) among children in a daycare setting compared with children not in daycare. The differences presumably were due to increased exposure to viral respiratory illnesses. Radiographic studies in children with acute colds regularly indicate abnormalities of the maxillary sinuses, suggesting that the infection involves these areas. These asymptomatic sinus opacifications may persist for 2 weeks after the symptoms of the upper respiratory tract illness have resolved. Viral infection that involves the sinuses rarely is differentiated from its primary manifestations, such as the common cold, nasopharyngitis, and influenza, and recovery is the rule. If the effect of the viral infection on the mucosal surface is severe and is associated with the inoculation of one or more pathogenic bacterial agents and obstruction of an ostium, disease occurs.

The mechanisms by which upper respiratory tract viral infections set the stage for secondary bacterial infection in the sinuses are complex. Using in situ hybridization, rhinovirus RNA was shown inside epithelial cells of maxillary sinus in 50% of a small number of adults with acute sinusitis. This finding is remarkable because in experimental rhinovirus infections, only a small percentage of nasal epithelial cells were noted to contain rhinovirus RNA. These differences may reflect only differences in inoculum between experimental and natural infection, but they may indicate heavier infection in the sinuses than in the nose. Symptoms in upper respiratory tract viral infections are not caused by extensive damage to ciliated nasal epithelium but rather to aspects of the host response (see Chapter 7 ).

Other irritants can set the stage for sinus infection. Swimming in ocean, lake, or chlorinated pool water can lead to sinus involvement. Drying of the nasal mucosa, which occurs commonly during the winter in cold climates, may be a precipitating factor.

Dental infections or extractions also can lead to maxillary sinusitis if the tooth root is adjacent to, or sometimes penetrating, the maxillary sinus floor. Sudden change in pressure, as with diving or during descent in an airplane, physically can overcome local mucociliary defense mechanisms and lead to the sudden onset of acute sinusitis.

A number of host factors and perhaps microbiologic factors are associated with recurrent and chronic sinusitis. *

* References .

Recurrent chronic sinusitis implies a problem with local mucociliary defense, a defect in systemic immunity, or a fixed anatomic sinus obstruction. Often, the predisposing factors work in tandem, as in a child with a septal deformity and a viral illness. In chronic sinusitis, the mucosa is thickened, and marked edema, vessel dilation, and infiltration of inflammatory cells are present. Goblet cells are decreased in density, and seromucous glands are increased in density compared with their presence in normal sinuses.

Children with respiratory allergies are prone to sinusitis, and allergy is the second most prevalent predisposing factor in childhood sinusitis, acting through mucosal congestion and perhaps depressing local and systemic immune responses. The treatment of respiratory allergies may contribute to sinusitis because ciliary damage occurring after the administration of nasal decongestants has been shown in organ culture and animal studies. Richards and colleagues reported a diagnosis of atopy in 62% of a selected cohort of pediatric patients who had documented recurrent sinusitis and were referred to allergy clinics in Los Angeles.

Defects of ciliary function, such as those occurring in cystic fibrosis, immotile cilia syndrome, and Kartagener syndrome, predispose a child to chronic sinusitis. Refractory sinusitis also occurs commonly in children with primary and acquired immunodeficiency diseases. Immunocompromised children undergoing treatment for malignancies and organ transplantations constitute a growing population with a potential for developing sinusitis that is difficult to manage. Finally, anatomic obstruction caused by septal and turbinate deformities, craniofacial anomalies, foreign bodies, adenoidal hypertrophy, or nasal masses or polyps predisposes children to sinusitis. Nasal polyps in young children usually are not caused by allergies and should be an indication for evaluation for cystic fibrosis. In addition, biofilms may play an important role in chronic sinusitis and are thought to produce persistent disease despite maximal medical and surgical therapy.

Immunologic mechanisms are important in the pathogenesis of sinus infections, as indicated by the high prevalence of chronic sinus infections in children with immunodeficiencies. Sinonasal mucus contains IgA, IgG, IgM, and lysozymes. Secretory IgA, which is produced locally, is the predominant immunoglobulin in nasal mucus. IgG antibodies in nasal mucus result from passive leakage from plasma cells in the epithelium and submucosa and from the serum. Generally, with the patient’s increasing age and as a result of previous exposures, these immunoglobulins develop species-specific and type-specific antibodies that block epithelial colonization by specific microorganisms.

Shapiro and associates studied 61 children with refractory sinusitis and found that 34 had abnormal immunologic studies. Abnormal findings included poor response to pneumococcal type 7 antigen after immunization, IgG3 subclass deficiency, low serum IgA or IgG values, and elevated serum IgE values.

Etiology

Table 14.1 lists etiologic agents of sinusitis by age of patient and type of illness. In all age groups and in acute, subacute, and chronic disease, Haemophilus influenzae and Streptococcus pneumoniae are the principal pathogens in most cases. Also, a large number of different bacterial species have been recovered from the sinuses of affected patients. In young children, more than 90% of all cases of sinusitis are caused by five organisms: H. influenzae, S. pneumoniae, Moraxella catarrhalis, Staphylococcus aureus, and Streptococcus pyogenes. Concern has been raised as to whether S. aureus is a cause of sinusitis in children. This concern is based on the fact that S. aureus is common in the noses of all children, and therefore there is likely contamination at the time of maxillary sinus puncture or endoscopic surgery. Similar concern should also be raised regarding α-hemolytic streptococci, coagulase-negative Staphylococcus, and various anaerobes because they also are part of the nasal flora. In adolescents, the same organisms, plus largely penicillin-sensitive anaerobes, account for most cases. As noted in Table 14.1 , a variety of gram-negative enteric and other bacilli have been recovered from patients with sinusitis, in most instances from patients who have had various forms of antibiotic therapy before culture. Organisms previously considered to be nonpathogens, such as Staphylococcus epidermidis, have been implicated etiologically.

Although clinically recognized sinusitis has occurred rarely in patients with Mycoplasma pneumoniae infection, Griffin and Klein noted radiographic evidence of sinusitis in approximately two-thirds of a group of U.S. Navy recruits with M. pneumoniae pneumonia. In adults with chronic suppurative maxillary sinusitis, mycoplasmas have been sought but not recovered. Bhattacharyya and colleagues noted L-forms in 21% of all sinuses in patients with chronic disease.

In a study of 25 adults with chronic rhinosinusitis, Chlamydophila pneumoniae was recovered from nasopharyngeal samples in 2 patients but not from any of 10 healthy controls. In addition, the patients were more likely than control subjects (20%) to have serum IgG antibody titers to C. pneumoniae of 1 : 64 or greater (72%). IgA antibody titers to C. pneumoniae of 1 : 32 or greater also were more prevalent in the patients (48%) than in the controls (10%). In a study involving 20 children with chronic sinusitis, Cultrara and colleagues cultured material from 13 bilateral endoscopic ethmoidectomies with maxillary antrostomies, 10 adenoidectomies, and 3 bilateral maxillary sinus lavages. They isolated C. pneumoniae from a nasopharyngeal swab and adenoid tissue from a 6-year-old child.

Fungal diseases of the sinuses have been well described in adults. Aspergillus spp. are the most common fungal causes of sinusitis. Many cases of chronic sinusitis from which a microorganism is not recovered have been thought to be caused by Aspergillus spp. infections. The presence of eosinophils, Charcot-Leyden crystals, and hyphae found retrospectively, and not noted on the original examination, in mucus recovered from sinuses suggests that some cases of chronic sinusitis may represent Aspergillus hypersensitivity. This allergic aspergillosis in the sinuses is similar to allergic bronchopulmonary aspergillosis. In a series of six patients who were 8 to 16 years of age and had allergic aspergillosis sinusitis, all presented with nasal polyposis and facial deformity, indicating advanced disease. Acute fulminant fungal sinusitis, such as mucormycosis, which is caused by Zygomycetes (formerly Phycomycetes), is seen in immunosuppressed individuals and is associated with high morbidity and mortality rates. Drechslera spp., Bipolaris spp., Scopulariopsis spp., Candida spp., and Curvalaria lunata can cause sinusitis in children.

Although sinusitis has been reported as a complication of Epstein-Barr virus infection, the sinus infections seem to be a complication of corticosteroid treatment and not specifically the viral infection. Nocardia spp. have been reported as a cause of acute sinusitis in an adult transplant recipient and of chronic sinusitis in immunocompetent and immunocompromised individuals.

Epidemiology

Although sinus involvement occurs commonly with viral infection of the respiratory tract, sinusitis seldom is identified as a specific illness in previously healthy children. In a survey of a total of 2613 office visits, Breese and colleagues noted only six children (0.23%) in whom the initial diagnosis was sinusitis. The true incidence of sinusitis in childhood is unknown. In 1989, Wald and colleagues estimated that 0.5% to 5% of upper respiratory tract infections are complicated by acute sinusitis. More recent estimates by the same authors have been 10%. The most recent estimates of greater incidence could be related to a heightened awareness and concern for lost work days by working parents, a possible correlation between pulmonary problems in an increasing number of children with chronic lung disease, better imaging techniques, increased interest in endoscopic sinus surgery, more disease because of more exposure as a result of more children being in daycare, and an increased recognition or perhaps incidence of allergy-related illness. Seasonal prevalence has not been studied, but a reasonable assumption is that disease would increase during the cold weather months because it is the time of greatest respiratory viral activity. Cases in older children also can be expected to occur more frequently in association with swimming.

Shapiro and colleagues used data from the National Ambulatory Medical Case Survey and National Hospital Ambulatory Medical Case Survey between 1998 and 2007 and found that the annual visit rate for acute sinusitis for children younger than 18 years of age ranged between 11 and 14 visits per 1000.

Although it is not well documented, sinusitis seems to be more of a problem in geographic areas where marked temperature changes occur. In children, sinusitis seems to occur more commonly in boys than in girls. Ueda and Yoto found abnormal findings in the maxillary sinuses in 135 (6.7%) of 2013 children who presented to an outpatient department with upper respiratory symptoms; of this group, 65% were boys and 35% were girls. Manning and associates found similar distribution in a group of 60 children diagnosed by CT or magnetic resonance imaging (MRI). Host factors are important in sinusitis because the illness occurs more commonly in allergic children; in children with chronic ear infections; and in patients with cystic fibrosis, primary humoral immunodeficiencies, and Kartagener syndrome. Although an association between sinus disease and asthma exists, controversy continues regarding whether sinusitis and other upper airway stimuli can induce asthma. A review of hospital admissions of patients with status asthmaticus at the Children’s Hospital of Los Angeles showed a marked increase in admissions, and sinusitis was diagnosed in 23%.

Sinusitis is noncontagious from person to person, but point-source outbreaks are possible from swimming in heavily contaminated water. A cluster of seven cases of invasive nosocomial fungal sinusitis in severely neutropenic patients has been described. It was caused by the release of airborne fungal spores from soil reservoirs that were distributed during hospital construction during a 2-year period.

Clinical Presentation

The clinical symptoms of sinusitis vary by age. Older children and adolescents have localized complaints similar to those of adults, whereas in young children the findings are related less clearly to the sinuses. The overall frequencies of symptoms, signs, and laboratory findings for acute, subacute, and chronic disease are presented in Table 14.2 .

In young children, disease involves only the ethmoidal and maxillary sinuses. In these children, illness frequently has its onset after they have had an upper respiratory tract viral infection. A period of general improvement may occur, however, between the acute respiratory illness and the onset of symptoms related to sinus infection. The most prominent symptom in all children, and particularly in children younger than 10 years of age, is persistent rhinorrhea. The discharge frequently is purulent, but it occasionally can be serous or watery. Associated with rhinorrhea is cough, which becomes more prominent with increasing duration of disease. The cough particularly is troublesome at night because it is caused by the stimulation of the sinus drainage as it traverses the pharyngeal wall. The posterior drainage also occasionally causes vomiting. Fever is a variable occurrence in sinusitis and generally is related inversely to age and duration of illness. Malodorous breath often is reported by parents. The first evidence of illness in some children is fever and periorbital swelling. In most instances, periorbital cellulitis is a manifestation of ethmoidal sinusitis.

Although facial pain and headache are frequent complaints of sinus disease in adults, they have been noted in only approximately one-third of the cases in children and are unusual occurrences in young children. The main symptom in older children and adolescents is rhinorrhea. In older patients with more chronic disease, the nasal symptoms may be minimal or absent. Troublesome postnasal drip is a frequent complaint.

Acute isolated sphenoidal sinusitis in children is rare but often misdiagnosed because the symptoms are vague and there are no specific physical findings. Findings include fever, headache, postnasal drip, and neurologic symptoms. Swimming and diving are possible predisposing factors.

Physical signs in sinusitis also differ by age. Nasal discharge is the most frequent finding in all age groups. Young children are more likely to have a serous or watery discharge, however, than are adolescents. Elevation of temperature occurs more commonly in acute disease and in association with orbital cellulitis. Sinus tenderness, a common finding in older patients, is noted only rarely in children. Particularly significant is tenderness with percussion of the upper molars. Examination of the throat frequently reveals free exudate. Occasionally the breath is malodorous.

The ears are abnormal in almost half of all patients with sinusitis. In acute disease in young children, it can be acute otitis media, but usually the findings are more suggestive of serous disease. Acute sinusitis frequently is unilateral, whereas chronic disease more often is bilateral.

Children with chronic sinusitis frequently have only minimal complaints. The parent notes that the child does not feel well and frequently reports that the child has had a persistent respiratory tract infection for months. In a series of children with chronic (>3 months) upper respiratory tract complaints who were referred to allergy clinics, 60% had sinusitis. In this study, the combination of moderate to severe rhinorrhea and cough with minimal sneezing was reported to have a specificity of 95% and a sensitivity of 38% in predicting the presence of chronic sinusitis. In the referred children in this study, sinusitis was found in 63% of atopic children and in 75% of nonatopic children.

Laboratory studies other than cultures and radiography are not useful in the evaluation of a child with sinusitis. Herz and Gfeller noted that in their study erythrocyte sedimentation rates were elevated in only approximately half of the patients, and leukocytosis occurred in only one-third. Generally, younger children with orbital cellulitis and ethmoidal sinusitis are more likely to have elevated sedimentation rates and white blood cell counts. The American Academy of Pediatrics (AAP) Subcommittee of Sinusitis and Committee on Quality Improvement has recommended that the diagnosis of acute bacterial sinusitis be based on clinical criteria in children who present with upper respiratory symptoms that are either persistent (nasal or postnasal discharge of any quality with or without daytime cough for >10 to 14 days) or severe (temperature >39°C [102.2°F] and purulent nasal discharge present concurrently for at least 3 or 4 consecutive days in a child who appears ill).