Diagnosing sinusitis

November 2001

---Philip A. Brunell, MD

A wonderful report on practice guidelines for sinusitis appears in the September Pediatrics. It discusses the diagnosis and treatment of sinusitis. Probably the most revealing statement in the report is that “the paucity of data did not allow for formal meta-analysis.” Frequently, it was necessary to rely on expert opinions. The panel was composed of a variety of special skills including allergists and radiologists. The committee was careful to identify the type of evidence used to support each of its conclusions. It restricts itself to “acute bacterial sinusitis,” which it defines as lasting less than 30 days. It recommends treatment only for “persistent” or “severe” acute disease.

The committee courageously deals with the most difficult problem, that of diagnosis. Here it must rely on “limited scientific evidence and strong consensus of the panel.” How does one distinguish between an upper respiratory infections (URI) and sinusitis? It is indicated that history will be more useful than physical examination especially in young children. Transillumination of the sinuses is unreliable in this age group and facial tenderness is not often discernable. A very useful distinction is made between an acute URI and acute sinusitis. In the former, one would find fever, generalized headache and myalgia followed by respiratory symptoms and later some purulent discharge.

In acute sinusitis, one would expect to find concurrent appearance of purulent discharge and fever lasting at least 3 to 4 days in a child who is moderately ill. Older children often complain of intense periorbital headache. It is clear however, that things may not always be this clear. I find that when an older child complains of throbbing or fullness in his head when bending over to tie sneakers, this is pretty suggestive.

The acute severe category seems to be a bit easier than the “persistent.” Nasal or postnasal discharge (of any quality) or daytime cough (which may be worse at night) or both, lasting from 10 days to a month may include a lot of kids with a variety of ailments. Recurrent URIs, particularly in children in out-of-home care where these infections are frequent, can fit this description. Persistent cough can be due to a variety of causes other than sinusitis. An allergist probably would recommend antihistamines. The difficulty in ascertaining what is truly sinusitis might account in part for the different results of therapy.

Can your local radiologist help? The American College of Radiology (their statement on sinusitis can be accessed on their Web site under “appropriateness” and then go to “pediatric”) generally discourages any type of procedure for diagnosis of acute sinusitis, including plain films, sonography, CT scan or MRI. One of the main problems is the nonspecificity of soft tissue findings estimated to be “abnormal” in one- third to one-half of studies. This is a particular problem after or during a URI when these studies are most likely to be needed. It is unlikely, for instance, to be helpful in differentiating persistent sinusitis from recurrent URIs. For chronic sinusitis or nonresponsive acute sinusitis, the college statement recommends coronal CT scans. One would imagine that the same problems with nonspecific soft tissue changes would prevail.

The guidelines do not deal in detail with chronic sinusitis defined as symptoms of cough, rhinorrhea or nasal obstruction lasting longer than 90 days. Yet, these and “recurrent acute bacterial sinusitis” with episodes separated by at least 10 days are entities that are likely to be the most difficult. They must be differentiated from frequent URIs which are not uncommon in toddler particularly those attending out-of-home care. Overdiagnosis of sinusitis in the latter group will result in excessive and futile use of antimicrobials.

There is a strong recommendation that acute bacterial sinusitis be treated. This is based on studies in adults and of Ellen Wald’s excellent study in children (Pediatrics. 1986;77:795). A more recent, very thoughtful report which appeared in Pediatrics [2001;107:619] is a bit disconcerting. This study, which is recommended reading, fails to support the usefulness of antibiotics for treatment of sinusitis. The enrollees were from 3 pediatric practices. Persistent cough and nasal obstruction and/or discharge lasting at least 10 days were frequent symptoms. Using ampicillin as recommended in the guidelines and used in Wald’s earlier study, did not appear to be any benefit. The authors concludes that better criteria are needed to determine those children who will benefit from therapy. In a British Medical Journal meta analysis of treatment of sinusitis [1998;317:632] they observe that the one placebo-controlled study that failed to show efficacy was that in which the entry criteria were least stringent.

Another recommendation of the second Pediatrics study is to delay therapy until symptoms have been present for 3 weeks. This, in recognition of the fact that most cases of acute persistent sinusitis are self limited. Which of the pediatric studies should we believe? The answer is both. Wald’s study was done in a university medical center, where entry criteria were quite strict, found efficacy. The study done in private offices, which may be closer to “real life,” did not.

In reviewing the bibliography at the end of the report, one can not help but be impressed by the number of citations that are 10 or 20 years old. Many are in journals of related specialties who would have seen patients in referral suggesting the frustration pediatricians have encountered with sinusitis. Many of the titles of the articles ask questions; eg, does this patient have sinusitis? Frequently there are extrapolations from otitis media or adult studies of sinusitis. The report does give us some very useful advice. But, it clearly states that the problem of sinusitis is still a “work in progress.”