Correct diagnosis important to distinguish sinusitis from URI

January 2003

NEW YORK CITY — The diagnosis of children with sinusitis should be made on the basis of clinical criteria, and imaging studies may not always be needed to confirm this diagnosis, said Ellen R. Wald, MD, at the 15th Annual Infectious Diseases in Children symposium here.

Sometimes, it is difficult to distinguish sinusitis from an upper respiratory tract infection (URI), which means some URIs are treated as sinus infections and given antibiotics needlessly. The American Academy of Pediatrics released a guideline in late 2001 to help with the management of this common disease.

“The major purpose of the guideline is to encourage the accurate diagnosis of acute bacterial sinusitis, the appropriate use of imaging procedures and the judicious use of antibiotics,” said Wald, who is professor of pediatrics and otolaryngology, and chief of the division of allergy, immunology and infectious disease at Children’s Hospital of Pittsburgh.

The diagnosis of acute bacterial sinusitis in children older than 12 months should be based on clinical criteria in children with upper respiratory symptoms that are either persistent or severe, she said. Persistent symptoms last more than 10 but less than 30 days and have not begun to improve. Most uncomplicated viral URIs will last between five and seven days. By that time, almost all symptoms have begun to improve, although the patient may not be completely symptom free, explained Wald, who is also a member of the Infectious Diseases in Children editorial advisory board.

“And so it’s the persistence of respiratory symptoms beyond day 10 which should make you think that your patient is experiencing a secondary bacterial infection,” Wald said. “The symptoms are nasal discharge of any quality — thick or thin, serous, mucoid or purulent — or daytime cough which may be worse at night or both,” she said.

Fever, headache and facial pain are variable.

In contrast to children with persistent symptoms, children with severe symptoms are ill looking with a high temperature and a purulent nasal discharge. The discharge and fever run concurrently for at least three consecutive days. “These youngsters need to be distinguished from toddlers who present with uncomplicated viral infections who may have a moderate degree of illness. Children with severe symptoms may have an intense headache that is above or behind the eye,” Wald said.

Imaging

Imaging studies are not necessary to confirm a diagnosis of sinusitis in children younger than 6 years of age. “This recommendation is based on good evidence and strong consensus that the addition of images in young children is of limited value,” Wald said. “However, because of the limited evidence in older children suspected to have acute sinusitis, this issue remains controversial.”

CT (computed tomography) scans of the paranasal sinuses should be reserved for patients in whom surgery is being considered. “The thinking here is that, when precise anatomic information is required, then the best image should be obtained.”

The AAP also recommended that antibiotics be used for the management of acute bacterial sinusitis. Wald reviewed two pediatric studies that looked at management.

A 1986 study done by Wald and her colleagues compared the effectiveness of amoxicillin and amoxicillin-clavulanate (Augmentin, GlaxoSmithKline) in treating pediatric acute sinus infections. Children were eligible for the controlled, randomized study if they were between the ages of 2 and 16 years, and presented with either persistent or severe symptoms.

Sinus radiographs were performed and were considered to be abnormal if they showed diffuse opacification, mucosal thickening or an air fluid level. Children with clinical signs and symptoms, as well as abnormal radiographs were randomized to receive amoxicillin, amoxicillin-clavulanate or placebo for 10 days and then were followed for the remainder of the month. On the third day of treatment, 45% of children receiving antibiotic were cured in contrast to 11% of children receiving placebo. By the tenth day of treatment, 79% of children receiving antibiotics were cured or improved compared with 60% of children receiving placebo.

Jane Garbutt, MD, and her colleagues from the University of Washington did another study published in 2001 that also looked at treatment. Children, 1- to 18-years-old, were eligible for this study if they presented with respiratory symptoms lasting more than 10, but less than 28 days. No radiographs were performed. Children with a temperature greater than 39° C, facial pain or swelling were excluded. Patients were randomized to receive low-dose amoxicillin, low-dose amoxicillin-clavulanate or placebo for 14 days and were followed for the remaining 28 days. During the study, no differences were observed among the groups either with respect to speed of recovery or overall cure rate.

Wald believes several areas in Garbutt’s study could explain the discrepancies between these two studies, including the lack of radiological evidence of disease, the exclusion of the sickest children who are most likely to benefit from antibiotics and the use of low-dose antibiotics. “In the year 2000, low-dose amoxicillin and amoxicillin-clavulanate may be an ineffective antibiotic for a cohort of children who harbor resistant organisms in their paranasal sinuses,” Wald said.

“Children with acute bacterial sinusitis can be expected to recover more quickly when treated with antibiotics than when treated with placebo, however, the differences between treated and untreated patients is in the range of 20% to 30%. It’s easy for me to imagine how these differences might be obscured by the inclusion of a cohort of older children who actually did not have sinusitis or by a cohort of children for whom low-dose amoxicillin or amoxicillin-clavulanate was an ineffective antimicrobial,” she said.

Still, she said the Garbutt study was important because it underscores the need for more pediatric studies.

Causes

Streptococcus pneumoniae accounts for 30% to 40% of cases. Moraxella catarrhalis and Haemophilus influenzae each cause 20%. Streptococcus pyogenes accounts for 4% and, in 25% of cases, the maxillary sinus aspirate is sterile. Fifty percent of H. influenzae and 100% of M. catarrhalis are ß-lactamase producing, and 25% to 50% of S. pneumoniae are resistant to penicillin. About half of the S. pneumoniae isolates are highly resistant and half are intermediate in resistance.

Amoxicillin first

Still amoxicillin should be considered first-line therapy. “The desire to continue to use amoxicillin as first-line therapy in acute bacterial sinusitis rests on the fact that it is effective most of the time, it has low toxicity, low cost and a narrow spectrum. Therefore, for most children with uncomplicated acute bacterial sinusitis, the recommendation is for amoxicillin at a dose between 45 mg/kg/day and 90 mg/kg/day in two divided doses,” said Wald.

For children with penicillin allergy, alternatives include cefdinir (Omnicef, Abbott), cefuroxime (Ceftin, Lifecycle Ventures), or cefpodoxime (Vantin, Pharmacia & Upjohn). For serious drug allergy, clarithromycin (Biaxin, Abbott) or azithromycin (Zithromax, Pfizer) is recommended.

Wald said the optimal duration of treatment is unknown. “My personal favorite is to treat patients until they are symptom-free and then for an additional seven days. This individual approach to duration of therapy ensures that every patient will receive at least 10 days of treatment and that we won’t be giving prolonged courses of antibiotics in children who have already recovered and, therefore, are unlikely to be adherent.”

Children with complications of acute sinusitis should be referred to an otolaryngologist, an infectious disease specialist, an ophthalmologist and an oral surgeon, she said.

Comparison of Clinical Course

Most uncomplicated viral URIs will last between five and seven days. By that time, almost all symptoms have begun to improve, although the patient may not be completely symptom-free.

Source: Ellen R. Wald, MD

For more information:

• Wald ER. Diagnosis and management of acute bacterial sinusitis. Presented at the 15th Annual Infectious Diseases in Children Symposium. Nov. 16-17. New York City.
• AAP Subcommittee on Management of Sinusitis and Committee on Quality Improvement. Clinical Practice Guideline: Management of Sinusitis. Pediatrics. 2001;108:798-808.
• Garbutt JM, Goldestein M, et. al. A randomized, placebo-controlled trial of antimicrobial treatment for children with clinically diagnosed acute sinusitis. Pediatrics. 2001; 107:619-625.
• Wald ER, Chiponis D, et. al. Comparative effectiveness of amoxicillin and amoxicillin-clavulanate potassium in acute paranasal sinus infections in children: a double-blind, placebo-controlled trial. Pediatrics. 1986;77:795-800.
• Dr. Wald has received research grant support from Abbott Laboratories, Pfizer and GSK, for whom she is also a consultant.