Chapter 031. Pharyngitis, Sinusitis, Otitis, and Other Upper Respiratory Tract Infections (Part 2)

Upper Respiratory Infections: Treatment Antibiotics have no role in the treatment of uncomplicated nonspecific URI. In the absence of clinical evidence of bacterial infection, treatment remains entirely symptom-based, with use of decongestants and nonsteroidal antiinflammatory drugs. Other therapies directed at specific symptoms are often useful, including dextromethorphan for cough and lozenges with topical anesthetic for sore throat. Clinical trials of zinc, vitamin C, echinacea, and other alternative remedies have revealed no consistent benefit for the treatment of nonspecific URI.Infections of the SinusSinusitis refers to an inflammatory condition involving the four paired structures surrounding the nasal cavities. ...
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Chapter 031. Pharyngitis, Sinusitis, Otitis, and Other Upper Respiratory Tract Infections (Part 2) Chapter 031. Pharyngitis, Sinusitis, Otitis, and Other Upper Respiratory Tract Infections (Part 2) Upper Respiratory Infections: Treatment Antibiotics have no role in the treatment of uncomplicated nonspecificURI. In the absence of clinical evidence of bacterial infection, treatment remainsentirely symptom-based, with use of decongestants and nonsteroidal anti-inflammatory drugs. Other therapies directed at specific symptoms are oftenuseful, including dextromethorphan for cough and lozenges with topical anestheticfor sore throat. Clinical trials of zinc, vitamin C, echinacea, and other alternativeremedies have revealed no consistent benefit for the treatment of nonspecific URI. Infections of the Sinus Sinusitis refers to an inflammatory condition involving the four pairedstructures surrounding the nasal cavities. Although most cases of sinusitis involvemore than one sinus, the maxillary sinus is most commonly involved; next infrequency are the ethmoid, frontal, and sphenoid sinuses. Each sinus is lined witha respiratory epithelium that produces mucus, which is transported out by ciliaryaction through the sinus ostium and into the nasal cavity. Normally, mucus doesnot accumulate in the sinuses, which remain sterile despite their adjacency to thebacterium-filled nasal passages. When the sinus ostia are obstructed, however, orwhen ciliary clearance is impaired or absent, the secretions can be retained,producing the typical signs and symptoms of sinusitis. The retained secretions maybecome infected with a variety of pathogens, including viruses, bacteria, andfungi. Sinusitis affects a tremendous proportion of the population, accounts formillions of visits to primary care physicians each year, and is the fifth leadingdiagnosis for which antibiotics are prescribed. It is typically classified by durationof illness (acute vs. chronic); by etiology (infectious vs. noninfectious); and, wheninfectious, by the offending pathogen type (viral, bacterial, or fungal). Acute Sinusitis Acute sinusitis—defined as sinusitis of Etiology A number of infectious and noninfectious factors can contribute to acuteobstruction of the sinus ostia or impairment of ciliary clearance, with consequentsinusitis. Noninfectious causes include allergic rhinitis (with either mucosal edemaor polyp obstruction), barotrauma (e.g., from deep-sea diving or air travel), orchemical irritants. Illnesses such as nasal and sinus tumors (e.g., squamous cellcarcinoma) or granulomatous diseases (e.g., Wegeners granulomatosis orrhinoscleroma) can also produce obstruction of the sinus ostia, while conditionsleading to altered mucus content (e.g., cystic fibrosis) can cause sinusitis throughimpaired mucus clearance. In the hospital setting, nasotracheal intubation is amajor risk factor for nosocomial sinusitis in intensive care units. Acute infectious sinusitis can be caused by a variety of organisms,including viruses, bacteria, and fungi. Viral rhinosinusitis is far more commonthan bacterial sinusitis, although relatively few studies have sampled sinusaspirates for the presence of different viruses. In those studies that have done so,the viruses most commonly isolated—both alone and with bacteria—have beenrhinovirus, parainfluenza virus, and influenza virus. Bacterial causes of sinusitishave been better described. Among community-acquired cases, S. pneumoniae andnontypable Haemophilus influenzae are the most common pathogens, accountingfor 50–60% of cases. Moraxella catarrhalis causes disease in a significantpercentage (20%) of children but less often in adults. Other streptococcal speciesand Staphylococcus aureus cause only a small percentage of cases, although thereis increasing concern about community strains of methicillin-resistant S. aureus(MRSA) as an emerging cause. Anaerobes are occasionally found in associationwith infections of the roots of premolar teeth that spread into the adjacentmaxillary sinuses. The role of Chlamydophila pneumoniae and Mycoplasmapneumoniae in the pathogenesis of acute sinusitis is still unclear. Nosocomialcases are commonly associated with bacteria found in the hospital environment,including S. aureus, Pseudomonas aeruginosa, Serratia marcescens, Klebsiellapneumoniae, and Enterobacter species. Often, these infections are polymicrobialand involve organisms that are highly resistant to numerous antibiotics. Fungi arealso established causes of sinusitis, although most acute cases are inimmunocompromised patients and represent invasive, life-threatening infections.The best-known example is rhinocerebral mucormycosis caused by fungi of theorder ...