TITLE: SINUSITIS IN CHILDREN
SOURCE: Dept. of Otolaryngology, UTMB, Grand Rounds
DATE: November 1, 1995
RESIDENT PHYSICIAN: Kyle L. Kennedy, M.D.
FACULTY: Ronald W. Deskin, M.D.
SERIES EDITOR: Francis B. Quinn, Jr., M.D.

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"This material was prepared by resident physicians in partial fulfillment of educational requirements established for the Postgraduate Training Program of the UTMB Department of Otolaryngology/Head and Neck Surgery and was not intended for clinical use in its present form. It was prepared for the purpose of stimulating group discussion in a conference setting. No warranties, either express or implied, are made with respect to its accuracy, completeness, or timeliness. The material does not necessarily reflect the current or past opinions of members of the UTMB faculty and should not be used for purposes of diagnosis or treatment without consulting appropriate literature sources and informed professional opinion."

INTRODUCTION:

The diagnosis of sinusitis is being made more often in the pediatric population. Although many clincians once doubted the existence of sinusitis as a separate clinical entity in this group of patients, it is now recognized by many primary care physicians and otolaryngologists as being distinct from other forms of upper respiratory tract infection in children. In otherwise healthy children, sinusitis is thought to complicate upper respiratory tract infections in as many as five percent of the cases. In other subgroups of patients, such as those with nasal allergy, cystic fibrosis, immunodeficiencies, or chronic pulmonary disease, the incidence is even greater. The degree of morbidity and the impact on the overall health and well-being of the children within these groups is often heightened as well. The signs and symptoms are often subtle and may wax and wane over an extended period of time. This aspect of sinus disease in children, and the fact that the history may be limited to the observations of the parent with a physical examination highly dependent upon the cooperation of the young patient, places greater emphasis on the newer diagnostic imaging modalities in evaluating the extent of sinus involvement. The purpose of this presentation is to discuss sinusitis in children in terms of its etiology and pathogenesis, diagnosis, medical and surgical management, and complications.

ETIOLOGY AND PATHOGENESIS:

Normal paranasal sinus function and health is dependent upon several variables, including proper mucociliary defense, adequate patency of the sinus ostia, and local as well as systemic immunity. Any condition which alters one or more of these variables may predispose to the development of acute or chronic sinusitis.

The respiratory epithelium of the sinonasal tract consists principally of a ciliated pseudostratified columnar epithelium upon which rests a blanket of mucus with an outer viscid gel layer and an inner thin, watery sol layer, and these together constitute the mucociliary apparatus. The cilia lie primarily within the sol layer, with only their tips contacting the gel layer. The cilia beat in a biphasic fashion with a rapid effective stroke to propel the layer of mucus in a forward direction, and a slower recovery stroke within the sol layer. The orientation of the cilia within a given sinus is specific, such that secretions are propelled toward the sinus ostia and from there toward the nasopharynx and oropharynx where these cleared secretions are subsequently swallowed.

Mucociliary Defense:
Alterations of mucociliary defense are most commonly the result of viral upper respiratory infection. Viral infection has been shown to alter ciliary function with a decrease in beat frequency and subsequent stasis of secretions. The incidence of viral upper respiratory infections has risen, possibly as a result of the increase in the number of children in the day care setting. Visits to the physician have also risen, with a significant amount of time lost from work by parents and further heightening of the impact of upper respiratory tract infections, including sinusitis. Nasal allergy is perhaps the second most common predisposing factor in the development of pediatric sinusitis and may be seasonal or perennial. The resultant mucosal edema causes obstruction of sinus ostia with decreased drainage and ventilation of the affected sinuses. Dessication by dry air and/or an alteration in the patterns of nasal airflow may lead to impaired mucociliary function by increasing the viscosity of secretions and alterations in the nasal epithelium, perhaps to the point of replacement of the normal epithelium with squamous metaplasia and loss of functional cilia.

Barotrauma as a result of swimming and diving or rapid ascent or descent may also overcome local mucociliary defenses with alterations in the clearance of secretions. Cystic fibrosis (mucoviscidosis) is an autosomal recessive condition manifested as impaired exocrine gland function with an increase in the viscosity of secretions. These patients suffer recurrent infections of both the upper and lower respiratory tracts with a large number of them demonstrating evidence of sinus disease. Alterations in the structure or function of the cilia themselves, as seen in primary ciliary dyskinesia, understandably impair the function of the mucociliary apparatus and are associated with episodes of recurrent otitis media, sinusitis, and pulmonary infection. Kartagener's syndrome serves as an example and consists of sinusitis, situs inversus, and bronchiectasis.

Anatomic Obstruction:
Anatomic obstruction of the sinus ostia encompasses a variety of conditions. Septal deviation of any significance is uncommon in children, and, unless quite symptomatic, is often best left untreated until later in the teenage years as there are concerns of altering nasal growth centers. Oddly, septal deviation has been known to result in sinusitis on the side opposite the deviation, possibly by the alteration of the inflow of air on the opposite side with dessication of the nasal mucosa and a resultant impairment of mucociliary clearance. Craniofacial anomalies, as seen in children with craniofacial dysostoses, cleft lip and cleft palate, and Down Syndrome are often associated with an increased incidence of sinusitis, as is choanal atresia. Foreign bodies in children are often notable for a unilateral foul-smelling rhinorrhea and may produce obstruction of the sinus ostia of sufficient degree and duration to produce an ipsilateral sinusitis. Of no small consequence are those foreign objects placed by healthcare personnel such as nasogastric and nasotracheal tubes. Intranasal tumors and polyps may also lead to obstruction. The appearance of nasal polyposis in a child is uncommon and should prompt a sweat chloride test in the evaluation for cystic fibrosis.
Immunity:
Primary and acquired immunodeficiencies may result in an increase in recurrent episodes of sinusitis which may be refractory to treatment. Local and systemic immunity play a role in the defense against bacterial invasion. Secretory IgA is found in nasal secretions, and serum IgG is essential as well. Intact cell-mediated immunity helps confer resistance against invasive fungal infections of the paranasal sinuses. The signs and symptoms of sinusitis in the immunocompromised child may be subtle and nonspecific, with nasal congestion, rhinorrhea, or chronic cough. Immunocompromise serves to dampen the host's response to the offending agent, thereby leading to a possible reduction in the degree of clinical or radiographic manifestations of sinus disease. An underlying immunodeficiency may also lead to infection with organisms which are atypical or more difficult to treat, such as resistant Gram positives, Gram negatives, anaerobes, of fungi.

The immune system in children normally undergoes a maturational process in which the components of cell-mediated and humoral immunity eventually rise to a level of immunocompetence equal to that of adults. The implication is that the pediatric patient is thus in a state of physiologic immunocompromise during the period of time that it takes for these functional changes to occur and may explain the predisposition of children to more frequent upper respiratory infections and why most children seem to "outgrow" this tendency. As an example, it is known that immunoglobulins such as IgG play a role in the defense against polysaccharide-encapsulated bacteria and that certain subclasses, namely IgG2 and Ig4, do not reach adult levels until approximately 10 years of age. In a child with refractory sinusitis in whom no other predisposing factors exist, measurement of immunoglobulin levels and various assays of immune function may demonstrate a deficiency more significant than the expected physiologic norm.

Selective IgA deficiency and common variable immunodeficiency are other examples of primary states often associated with an increased frequency of pediatric sinusitis. Imunosuppressive therapy employed in organ transplantation and chemotherapy utilized in the treatment of neoplastic disease has produced a subset of pediatric patients with iatrogenic immunocompromise and predisposition toward many kinds of infection, including sinusitis. Maternally-acquired AIDS and AIDS acquired as a result of transfusion of blood products is another cause of immunodeficiency in the pediatric age group. The suspicion of sinusitis in the immunocompromised child with its potential for substantial morbidity in this patient population requires timely evaluation and intervention.

Chronic pulmonary disease:
It has long been postulated that a relationship exists between the upper and lower respiratory systems such that sinonasal and lower respiratory tract function are intimately connected via a complex and poorly understood neurologically mediated reflex pathway. Investigators have thus far been unsuccessful in elucidating the exact mechanism by which this phenomenon occurs. Anecdotal evidence exists concerning exacerbation of chronic lower respiratory disease coinciding with the appearance of rhinosinusitis in the patient with preexisting pulmonary disease. Conversely, improvement in lower respiratory tract symptoms have been noted following adequate treatment of sinonasal disease. The alteration of normal nasal physiologic function with disease in this area results in a loss of filtering and conditioning of the ispired air which may have a detrimental effect on already tenuous lower respiratory tract function.

Asthma is a common pulmonary disease in the pediatric population, and an increase in its incidence has been noted in recent decades. The occurrence of upper respiratory tract infections in these patients may be more frequent with an increase in predisposition toward the development of sinusitis. The sinusitis may then serve to create an exacerbation in pulmonary symptoms in the asthmatic patient, resulting in significant morbidity and a further negative impact on overall health and well-being in these children.

Cystic fibrosis (also known as mucoviscidosis) is a common genetic disease of autosomal recessive inheritance which may be thought of as a generalized defect in exocrine gland function throughout the body. An increase in the viscosity of the secretions of various organs result in the common manifestations of this disease, including recurrent sinopulmonary and gastrointestinal disease. Patient age at the time of presentation is variable with the majority of cases being detected in infancy or early childhood. Increased viscosity of nasal secretions results in impairment of mucociliary function and stasis. Bacterial infection often ensues, leading to chronic sinusitis. Nasal polyposis may be noted in these patients, and the appearance of nasal polyps in an otherwise healthy child should prompt an evaluation for the presence of cystic fibrosis with a sweat chloride test. Pseudomonas is often detected in cultures obtained from these patients and requires appropriate antibiotic coverage during medical management.

Microbiology:
Studies to discern the bacteriology involved in the development of pediatric sinusitis have been relatively few in number. This may be due at least in part to the inaccessibility of the paranasal sinuses in children and the inherent difficulty in obtaining sinus aspirates for culture. Most studies involve aspirates obtained from the maxillary sinuses. Viral upper respiratory infection is known to be associated with the development of sinusitis, and although viral cultures obtained from sinus aspirates are very rarely positive, viruses are known to predispose to subsequent bacterial infection via such mechanisms as viral-induced impairment of the mucociliary apparatus.

The bacterial pathogens most commonly implicated in acute sinusitis are similar to those found in otitis media, including Streptococcus pneumoniae, Moraxella catarrhalis, and Hemophilus influenzae (non-typable). These same aerobic organisms are commonly found in subacute and chronic sinusitis as well. However, other aerobes such as Staphylococcus and alpha-hemolytic Streptococcus are noted to be more prevalent in chronic sinusitis, as are anaerobes like Peptococcus, Peptostreptococcus, and Bacteroides. Pseudomonas aeruginosa is often cultured from patients with cystic fibrosis.

Fungal infections of the paranasal sinuses are most frequently seen in those patients with some form of immunodeficiency. Some of the pediatric patients at highest risk are those receiving immunosuppressive therapy following organ transplantation or chemotherapy for the treatment of neoplastic disease. Aspergillus is a common offender in this patient population, and treatment involves the administration of systemic anti-fungal agents.

DIAGNOSIS:

Signs and symptoms:
As previously mentioned, the signs and symptoms of sinusitis in children are quite often subtle and nonspecific and may wax and wane over an extended period of time. The typical uncomplicated viral upper respiratory infection usually resolves within 5-7 days. Symptoms may not have resolved completely by 10 days, but clinical improvement should have been noted by this time. Should symptoms of upper respiratory infection persist beyond 10 days without evidence of improvement, the possibility of the development of sinusitis should be considered. Also, the symptoms of a "cold" which seem more severe than usual and are accompanied by a fever of >39 degrees Celsius should raise this suspicion.

Symptoms may be quite difficult to distinguish from viral upper respiratory infection or allergic inflammation, the two most common predisposing factors in the development of sinusitis in children. Nasal discharge is of variable appearance and consistency and may be thin, thick, or mucoid with a predominantly clear appearance or obviously purulent. Nasal airway obstruction is a common complaint, as is cough, which often occurs during the day and then worsens at night. Facial pain and headache, which may be described by older children, are less common in the younger patient. However, the younger child may demonstrate irritability. Fever, when present, is often low grade. More significant fever accompanied by purulent rhinorrhea is most often noted in acute cases of sinusitis. There may also be postnasal drip and malodorous breath noted.

Physical examination:
The physical examination in pediatric patients with sinusitis is often unrewarding. Inspection should begin during the history-taking portion of the evaluation when evidence of nasal obstruction, rhinorrhea, or cough may become apparent. There may be hyponasal speech or dark discoloration of the lower eyelids. Stigmata of nasal allergy may be evident, such as facial pruritus indicated by the classic "allergic salute".

Physical examination is limited by the inaccessibility of the paranasal sinuses and the sometimes uncooperative nature of the pediatric patient. Anterior rhinoscopy is usually all that is possible in these patients, and if adequately performed, may yield useful information. Older children may tolerate examination with a nasal speculum, but for the younger patient, an otoscope is a useful diagnostic tool for visualization of the nasal cavity. There may be evidence of nasal mucosal edema or erythema, and purulent secretions may noted. Polyps may be visualized, as well as anterior septal deviations. It is important to attempt visualization of the middle meatus by directing attention in a posterosuperior fashion toward the medial canthus in order to inspect the middle turbinate and then the middle meatus, where purulent secretions may be noted. The osteomeatal complex, as the area of drainage for the frontal, maxillary, and anterior ethmoid sinuses, necessitates careful attempts at inspection of the all-important middle meatus for purulent secretions or other signs of pathology. Examination of the oropharynx may reveal evidence of purulent secretions or tonsillar disease. Due to the small size of the sinuses in the pediatric patients and the amount of intervening soft tissue and bone, transillumination of the sinuses is felt to be of little diagnostic value.

Radiographic evaluation:
Historically, plain radiographs have been obtained as the initial study in the evaluation of the paranasal sinuses, but in the absence of complete sinus opacification or an air-fluid level, their findings may correlate poorly with clinical evidence of disease. Plain films also provide inadequate evaluation of the ethmoid sinuses in most instances.

Computed tomography has evolved as the study of choice for evaluating the presence and extent of sinus disease. It has the ability to provide resolution of both bone and soft tissue, and coronal views through the paranasal sinuses and area of the osteomeatal complex provide essential anatomical information for those patients undergoing preoperative evaluation. Indications for obtaining a CT of the sinuses include evidence of severe, persistent sinus disease following maximal medical therapy, sinus disease in the immunocompromised patient, and suspicion of a suppurative complication of sinus disease. Of significant interest is the finding of some degree of sinus mucosal thickening in a significant number of patients having no evidence of sinus disease for whom CT studies were obtained for other reasons. This emphasizes the need to correlate radiographic findings with clinical evidence of disease in the therapeutic decision-making process and that CT findings, in and of themselves, do not constitute an indication for intervention. Disadvantages of computed tomography include exposure of the patient to ionizing radiation and the need for the use of sedation in some younger patients in order to obtain an adequate study.

MANAGEMENT:

The management of sinusitis in the pediatric population encompasses a spectrum of interventions, ranging from the safer, more conservative medical therapeutics on the one hand to the more invasive surgical therapeutics on the other. Efficacy and safety are the key issues, particulary since these interventions are being applied to a disease process which, in its uncomplicated form in the otherwise healthy patient, is often observed to resolve spontaneously in a large number of cases. Medical therapy is the mainstay of treatment with the majority of patients experiencing resolution of their sinus disease. Surgery is viewed as an adjunct to medical therapy and is reserved for those patients in whom complications arise or who have comorbid conditions or disease which is particularly refractory to medical management.
Medical Therapy:
Conservative medical therapy may begin with an attempt to improve nasal hygiene with a spray of a pH neutral saline preparation to each nostril once or twice daily. This serves to mechanically remove potential allergens and improve mucociliary function by increasing humidification. Attempts at irrigation may carried one step further with the Proetz procedure in the hopes of irrigating sinuses with incomplete occlusion of their ostia. With the patient in the supine position and the head hyperextended, the nose and nasopharynx are partially filled with a saline solution to which a topical decongestant may be added. Suction is then applied to one nostril while the other is occluded in order to remove the irrigating solution along with the secretions. These steps may be repeated in order to achieve irrigation and drainage of the sinuses.

The use of antihistamines and topical or oral decongestants has an uncertain role in the management of upper respiratory infections but have not been shown to prevent these infections nor significantly alter their course. These preparations are probably best employed for short-term symptomatic relief. Theoretically, these medications should result in decreased mucosal edema with improved patency of sinus ostia and an increase in the clearance of secretions. However, their use may result in drying of the mucosa and thickening of secretions with further impairment of mucociliary function.

Specific antimicrobial therapy is essential in the management of sinusitis. Antimicrobial coverage should include the most common organisms, Streptococcus pneumoniae, Moraxella catarrhalis, and Hemophilus influenzae. A significant number of isolates of Moraxella catarrhalis and Hemophilus influenzae have been shown to be producers of beta lactamase and may require administration of a broader spectrum, beta lactamase-resistant antibiotic for adequate coverage. There is some uncertainty as to the appropriate length of treatment, but for uncomplicated acute sinusitis, a 10-14 day course of amoxicillin at a dose of 40 mg/kg per day divided in three doses has been found to be efficacious. Improvement is ususally seen within 48-72 hours after starting treatment. If symptoms have not improved during this time, an alternative antibiotic should be considered, possibly one which is beta lactamase-resistant, such as amoxicillin-potassium clavulanate. Other alternatives include erythromycin ethylsuccinate-sulfisoxazole, trimethoprim- sulfamethoxazole, or cefuroxime axetil. If symptoms have improved but not completely resolved by the end of a standard course of therapy, an additional 7 days of therapy may be indicated.

For the treatment of recurrent or chronic sinusitis, a more lengthy course of therapy, usually with a beta lactamase- resistant antibiotic, is desirable. Most clinicians advocate a 3-4 week course of an appropriate antibiotic. Anaerobes should also be considered in the treatment of chronic sinusitis. In the immunocompromised patient, prophylactic antibiotic regimens are often utilized in addition to aggressive general management. Commonly used regimens include amoxicillin 20 mg/kg once daily and sulfisoxazole 30 mg/kg twice daily.

In the patient with nasal inhalant allergy, therapy begins with avoidance of the offending allergen(s). Topical nasal steroids such as beclomethasone dipropionate have been approved for use in children age 6 years and older and may provide long- term benefits. Cromolyn sodium, administered intranasally, stabilizes mast cells thereby preventing degranulation and release of histamine and other inflammatory mediators. It is most effective if administered prior to encountering the specific sensitizing allergen. For those patients in whom specific sensitizing allergens have been identified, immunotherapy may prove beneficial.

Surgical Therapy:
Surgical therapy for sinus disease may broadly be classified into indirect sinus procedures and direct sinus procedures. Indirect sinus procedures are those which attempt to improve sinus function without directly involving the sinuses. Direct sinus procedures involve surgical manipulations of the sinuses themselves.

Examples of indirect procedures are septoplasty and adenoidectomy. Septal deviation of sufficient degree to cause nasal obstruction and ipsilateral sinusitis is uncommon in the pediatric population but may benefit from limited septoplasty. Adenoidectomy is of limited value in the management of sinusitis. However, in appropriately selected patients with an adenoid pad large enough to result in nasal obstruction, adenoidectomy may be a reasonable first choice in the attempt to alleviate the symptoms of chronic sinusitis.

Antral lavage is probably the most commonly performed direct sinus procedure, and sinus aspiration may be achieved via a puncture site usually placed in the inferior meatus. The sinus aspirate may then be used for culture and sensitivity studies in order to appropriately tailor antimicrobial therapy. The evaluation is limited to the maxillary sinus and is not without the possibility of significant complication, including injury of orbital contents. The procedure is probably of greatest value the evaluation of sinusitis in the immunocompromised patient in whom rapid identification of the offending pathogen is of utmost importance.

Nasal antral windows are used to promote sinus drainage and ventilation and are often placed in the inferior meatus. Their long-tern efficacy in the pediatric population has been questioned, and a significant number of the windows have been found to lose patency with a subsequent recurrence of sinusitis. The mucociliary apparatus within a given sinus is oriented such that sinus secretions are propelled toward the natural sinus ostia, often bypassing the nasal antral window in the dependent area of the sinus. If sufficient disease exists to significantly impair mucociliary function or if primary ciliary dysfunction is present, gravity may play a larger role in enhancing sinus drainage via the dependent window thereby increasing its efficacy.

The Caldwell-Luc procedure is less frequently used as a method of maxillary sinus drainage due to concerns of potential damage to the unerupted permanent dentition and the uncommon finding of sinus disease of a sufficiently extensive and irreversible nature as to benefit from removal of sinus mucosa.

Middle meatal antrostomy attempts to promote drainage and ventilation of the maxillary sinus by opening the natural sinus ostium thereby enhancing the natural clearance of secretions. This procedure has been shown to be effective but has the disadvantage of not addressing disease of the anterior ethmoid sinuses, which are more frequently involved than the maxillary sinuses.

Interest has grown in recent years with regard to the application of the techniques of functional endoscopic sinus surgery in the treatment of sinus disease in children. Endoscopic sinus surgery in the pediatric patient is challenging to say the least. The small space of the nasal cavity in these patients and the proximity of the lateral nasal wall to the contents of the orbit and anterior cranial fossa make serious complications a very real possibility. However, these techniques may be performed in a safe manner and have been shown to be effective. The indications are not well-defined but include therapy for suppurative complications of sinus disease, severe sinusitis leading to exacerbation of comorbid conditions, and chronic sinusitis unresponsive to maximal medical management having a significant impact on overall health and well-being. Most procedures involve maxillary antrostomy with anterior or anterior and posterior ethmoidectomy. Achieving the maximum amount of benefit with the least amount of anatomical manipulation at the osteomeatal complex is the goal. A pre- operative coronal CT is essential in defining the location and extent of disease as well as the pertinent anatomy at the site of the proposed endoscopic procedure.

COMPLICATIONS:

Suppurative complications of acute and chronic sinusitis are most often orbital or intracranial and require rapid diagnosis and treatment. Orbital complications are most common and are more likely to occur in younger children. The infectious process usually reaches the orbit by direct extension. A system has been suggested by Chandler which is clinically useful in categorizing the extent of orbital involvement and aids in selection of the appropriate therapy. Preseptal orbital inflammation suggests nontender eyelid edema with no loss of ocular mobility or visual acuity. Orbital cellulitis results in diffuse infection of the orbital contents without abscess formation. Subperiostial abscess formation involves the space between orbital periostium and the bony wall of the orbit. There is often asymmetric proptosis with displacement of the globe in an inferolateral direction with decreased ocular mobility and visual acuity. Orbital abscess formation usually results in severe symmetric proptosis with worsening ocular mobility and visual loss. Cavernous sinus thrombosis may occur with sphenoid sinusitis and involves further posterior extension of the infection. This may result in bilateral symptoms. Orbital complications are best evaluated with axial computed tomography. Initial therapy usually consists of aggressive intravenous antibiotic therapy with surgical drainage directed by the presence or absence of discrete abscess formation.

Intracranial suppurative complications are more often seen in older children and include meningitis, epidural abscess, subdural abscess, and brain abscess. Epidural abscess is the most common and the frontal lobes are most often involved in brain abscess formation. Patients may display fever, headache, nuchal rigidity, altered mental status, or focal neurologic signs. Aggressive intravenous antibiotic therapy is again directed toward the most common offending pathogens with surgical therapy dictated by the location and degree of intracranial involvement.

CONCLUSIONS:

Sinusitis in children is now recognized as a distinct clinical entity which may have significant morbidity. Medical management remains the mainstay of therapy with surgery reserved for those patients in whom sinus disease represents a significant threat to overall health despite maximal medical management. Further inquiry is required to expand our understanding of the etiology and natural history of sinus disease with additional definition of the indications for specific forms of medical and surgical therapeutic intervention.

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