March 1996
MIAMI BEACH, Fla.—It is a difficult decision: determining when, if ever, in the course of a viral upper respiratory infection (URI) to prescribe antimicrobial agents. Whether to use them to shorten the course of the clinical illness or to prevent serious complications is a question pediatricians often ask themselves, said Ellen R. Wald, MD, here at the Fifth Annual Masters of Pediatrics meeting.
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Determining whether a secondary bacterial infection exists is not always easy, she said, but a few good rules help one make that decision.
Among them is classifying the clinical syndromes of sinusitis into three discrete categories: acute sinusitis, which lasts 10 to 30 days; subacute sinusitis, which lasts 30 to 120 days; and chronic sinusitis, which lasts longer than 120 days.
The bacteria implicated in these infections
includes Streptococcus pneumoniae; Moraxella catarrhalis; and
Haemophilus influenzae.
The most common presentation of a secondary bacterial infection is the
onset of persistent symptoms. The course of most simple viral URIs is 5 to 10
days. Although the child may not be free of symptoms by the 10th day, their
respiratory symptoms have almost always peaked in intensity and have begun to
improve.
"Failure to improve should make you suspicious of a secondary infection," said Wald, Professor of Pediatric Otolaryngology, University of Pittsburgh School of Medicine, and Chief, Division of Pediatric Infectious Diseases, Children's Hospital of Pittsburgh.
Persistent symptoms last more than 10 but fewer than 30 days, and importantly, do not improve. The symptoms include nasal discharge of any quality, a daytime cough, low-grade or no fever, and occasionally, periorbital swelling.
"These children do not look very ill, nor do they complain of facial pain or headache. They come to your office not because they are very sick but because the symptoms won't go away," she said.
Less common, but equally important, is severe onset of disease, which is defined as a combination of high fever: above 39° C, purulent nasal discharge, headache, and occasionally, periorbital swelling. This combination of symptoms persists for 3 to 5 consecutive days and differentiates this condition from a simple cold.
"Children who present with severe symptoms may have headaches above or behind the eyes," she said.
If you think the patient has secondary bacterial infection of the paranasal sinuses, three confirmatory tests may help make the diagnosis: sinus aspiration, transillumination, and radiography.
A sinus radiograph with anteroposterior, lateral, and occipitomental views is the most common test. The most frequent findings in children with acute sinusitis are diffuse opacification and mucosal thickening of more than 4 mm.
"Mucosal abnormalities are very common in patients with respiratory complaints of any duration. Most viral URIs result in rhinosinusitis with radiographic abnormalities that indicate inflammation, but don't inform us whether the inflammation is caused by infection (viral or bacterial) or allergy.
The clinical syndrome of subacute sinusitis includes respiratory symptoms of 30 to 120 days with nasal discharge, daytime cough, intermittent fever, headache, and malodorous breath.
"These are children who may have been treated with an inappropriate regimen of antimicrobials, or whose treatment course has not been long enough," she said.
The bacteria involved are similar to those seen in acute sinus infection.
Those with chronic sinusitis (longer than 120 days) present with nasal discharge and congestion, cough, or both.
"When nasal congestion is very prominent and leads to nasal obstruction, these children become mouth breathers," she said. Halitosis, sore throat, intermittent fever, and headaches are also noted.
These children belong in two categories: the first group has an underlying condition that predisposes them to recurrent acute sinusitis, for example, an anatomic abnormality or immune deficiency. The other group has the signs and symptoms that mimic chronic sinusitis, but may be caused by other problems.
This latter group can be further divided into three categories. The first have very closely spaced URIs that seem to coalesce. The second group has an allergic or non-allergic rhinitis. The third group has reactive airway disease; the most common manifestation in this group is cough variant asthma.
"They complain of nasal symptoms and cough; these symptoms do not improve no matter what the treatment. First, they are diagnosed with acute sinusitis and given antibiotics. Then they are labelled as having sub-acute sinusitis. Finally, they are diagnosed with chronic disease because they have nasal symptoms and cough that do not improve," Wald said.
The confounder here is that children who have allergic rhinitis may actually get obstruction of the ostia and secondary bacterial infections as a result. "We have clinical symptoms that mimic sinusitis but also may be caused by true sinusitis," she said.
The clue to making this diagnosis is that when these patients receive antibiotics, although they get much better, their symptoms never abate. Within a few weeks after the antibiotics are withdrawn, the child relapses.
Children with asthma also confuse the picture. They, of course, do not respond to antimicrobial agents because they require bronchodilators, she explained.
Wald recommends amoxicillin as the first-line therapy in children with uncomplicated acute sinusitis because "it works most of the time and is safe and inexpensive."
Pediatricians should be mindful of safety issues, especially when treating uncomplicated cases because "we want to ensure that the cure is not worse than the illness," she said.
If patients do not respond to amoxicillin, if they live in an area with a high prevalence of beta-lactamase-producing organisms, or if they present with complicated or recurrent disease, then physicians may want to treat with amoxicillin clavulanate, erythromycin/sulfisoxazole, cefuroxime axetil, or cefixime, she said.
When given the appropriate drug, the vast majority of patients have a rapid diminution in their respiratory symptoms. For these patients, a 10-day course is sufficient, Wald said.
For those who respond more slowly, a longer regimen is indicated. She suggests treating these patients until they are free of symptoms, and then for an additional 7 days.
"This course buys more time for the patient during which the mucosa continues to heal, and therefore becomes more disease resistant," she said.
Presented at the Fifth Annual Masters of Pediatrics meeting, Miami Beach, Fla, Jan 25-29, 1996.
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