The clinical presentation of sinusitis in the pediatric patient is quite variable.
In younger patients there are no specific localizing symptoms and complaints often overlap with those heard in patients with nasal obstruction or allergies, thus obscuring the diagnosis. Our understanding of chronic sinusitis in the pediatric population is limited by the multifactorial nature of the disease. Because both the immune response and the anatomy are developing in children, there is reason to believe that the pathophysiology of pediatric sinusitis is different from sinusitis in adults.

Estimates of the incidence of sinusitis are hampered by the lack of precise definitions and diagnostic criteria. Wald et al has estimated that 0.5% to 5% of all upper respiratory tract infections are complicated by acute sinusitis. The average child has between 6 and 8 URIs per year, making sinusitis a common problem in the pediatric population.

Few studies have examined the microbiology of chronic sinusitis in the pediatric population, and studies that have addressed the issue have supported different conclusions. Brook, in 1981, evaluated patients who had sinus "symptoms" for 3 weeks. Culture of the maxillary antrum revealed a predominance of anaerobic organisms. More recent studies using stricter inclusion criteria have not supported this finding; Lusk and coworkers demonstrated aerobic Staphylococcus, Streptococcal species, Hemophilus and Moraxella in ethmoid bulla of patients undergoing endoscopic sinus surgery.

Cultures obtained from the maxillary antrums of children with acute sinusitis reveal a predominance of Streptococcus pneumoniae followed closely by Moraxella and Hemophilus influenzae. Unfortunately no studies exist that were performed in children in which bacteriologic efficacy has been assessed by sinus culture before and after treatment. From the adult literature there are 4 separate series of patients which include 194 patients. Bacteriologic cure rates after 10 days of oral antibiotics averaged 91% (range 71% to 100%). According to Wald et al. the spontaneous cure rate of acute sinusitis is 40%. Most patients respond to an initial course of Amoxicillin. Again, there do not exist studies that examine the optimum duration of treatment for acute sinusitis. Most patients respond clinically within 48 to 72 hours of initiating antibiotic treatment. Treatment is carried out 1 week past the resolution of symptoms. For more protracted courses of sinusitis, therapy is extended to 30 days. An interesting and as yet unstudied issue is the role of prophylaxis in patients with recurrent acute sinusitis.
Tonsil and adenoid hypertrophy may present with many of the same symptoms as chronic sinusitis. Investigations have shown an association with adenotonsillitis and sinusitis; however, most of these papers were retrospective and/or lacked follow-up. The role of tonsillectomy and adenoidectomy in the treatment of chronic sinusitis remains unclear.
Obstructive adenoid tissue may predispose to nasal obstruction and sinusitis, but no well- designed work supports this premise in a scientific fashion. The effectiveness of antral lavage has had mixed reviews in the literature.
Creation of a nasal-antral window through the inferior meatus is a technique that disregards the natural pattern of mucociliary flow. These windows almost never remain patent.

Muntz and Lusk reviewed the St. Louis experience with inferior meatal antrostomies in 1990 and found that this procedure was not appropriate as a primary modality except in children with ciliary dyskinesia. A more physiologic approach to the paranasal sinuses appears to be the middle meatal antrostomy. Kennedy in 1987 studied 75 patients in whom 117 middle meatal antrostomies were performed. Of the patients who were followed for more than 4 months, 98% had patent ostea. Ninety-two of these patients were symptom free or had a marked reduction of symptoms.

Endoscopic ethmoidectomy in children is a relatively new modality and the indications for surgery are still not well-defined. Most patients have undergone maximal medical therapy as well as appropriate workup for allergies, cystic fibrosis and underlying immune deficiencies. Unfortunately, "maximal medical therapy" has not been well-defined.
There is emerging a group of patients in whom the efficacy of endoscopic sinus surgery is becoming clear. Lusk and Parsons have shown that up to 80% of patients with either reactive airway disease or debilitating symptoms that interfere with daily life will have reduction of their symptoms.