"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."
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.
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.
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.
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.
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.
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.
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 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.
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.
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.
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.
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.
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