Upper Respiratory Tract Infections (Case 48)

Chapter 56
Upper Respiratory Tract Infections (Case 48)

Patricia D. Brown MD

Case: A previously healthy 33-year-old woman presents with a 4-day history of sneezing and runny nose accompanied by nasal congestion, sore throat, and a feeling of fullness in the ears. For the past 2 days she has had a cough, which was initially dry but is now productive of yellowish sputum. She denies fever, chills, or dyspnea. She does complain of generalized myalgias and malaise. Her toddler is currently recovering from a “cold.” She states that she feels she has a cold as well and would normally not seek medical attention, but she is leaving on a business trip in the morning and would like to begin antibiotic therapy “just in case” she has a bacterial infection that could worsen while she is on her trip. Her physical exam reveals normal vital signs; she has erythema of the posterior pharynx with tonsillar enlargement but no exudates. The tympanic membranes are mildly erythematous bilaterally, with no evidence of fluid or retraction. There is no palpable lymphadenopathy in the neck, and the lung examination reveals only a few scattered expiratory wheezes bilaterally.

Differential Diagnosis

Viral rhinosinusitis (VRS) (common cold)

Acute bronchitis

Otitis media (OM)

Acute community-acquired bacterial sinusitis (ACABS)

Pharyngitis (viral or bacterial)


Speaking Intelligently

Infections of the respiratory tract are extremely common in both children and adults and are a leading cause of acute-care visits to the physician. Most of these are infections of the upper respiratory tract (URIs), but the possibility of community-acquired pneumonia must also be considered in patients with an illness characterized by acute cough. URIs are more common in the fall to early spring, and the vast majority are due to viruses. Adults can be expected to have two to four colds per year; parents of preschool and young school-aged children experience the highest incidence of URI.


Clinical Thinking

• My first task is to try to differentiate URIs such as the common cold, sinusitis, acute bronchitis, pharyngitis, and OM from lower respiratory tract infections (pneumonia).

• Once I have determined that my patient has an infection confined to the upper respiratory tract (URI), the next challenge is to differentiate viral infection from bacterial infection. This differentiation is important, as viral infections will not require antibiotic therapy, although many patients—such as the woman in the case presented here—will present to the physician with an expectation for an antibiotic prescription.

• The single exception is influenza, which may be treated with antiviral therapy, although the benefits in otherwise healthy adults are very modest.

• Acute respiratory tract infections account for the majority of antibiotic prescriptions given to adults in ambulatory practices in the United States, and many of these prescriptions are given for infections that are viral in etiology.

• In addition to increasing costs and exposing patients to unnecessary risk of untoward medication effects, inappropriate antibiotic use is believed to be an important factor in increasing the prevalence of antimicrobial resistance among bacteria that cause both upper and lower respiratory tract infections, especially Streptococcus pneumoniae.


• Focus on careful elucidation of the constellation of symptoms and the temporal course of the illness.

• The constellation of symptoms is important in pharyngitis, for example, where the presence of cough makes the likelihood of viral infection much greater.

• The temporal course of illness is of critical importance in trying to differentiate VRS from ACABS. Patients with purulent nasal discharge and facial pain or tenderness (especially if unilateral), who are not improving or are worsening after 7 days of illness, are more likely to have a bacterial sinusitis.

• History of sick contacts is also important; sick contacts with URI symptoms support a diagnosis of viral infection, while an adult patient with pharyngitis who has been exposed to a person with documented streptococcal pharyngitis is at higher risk for having this pathogen as the etiology of his or her infection.

• Emphasize that the presence of purulent respiratory secretions simply reflects inflammation (the presence of polymorphonuclear neutrophils [PMNs]), which may be elicited by either viral or bacterial infection.

• In patients with acute coughing illness, the presence of pleuritic chest pain should prompt further investigation to exclude pneumonia.

• Influenza virus can cause VRS and acute pharyngitis.

Physical Examination

• Evaluate the temperature, respiratory rate, and pulse.

• Examine the upper respiratory tract, including palpation over the maxillary and frontal sinuses, and carefully examine the posterior pharynx for the presence of tonsillar enlargement, erythema, and exudates.

• Note conjunctival injection.

• Examine the tympanic membranes in adults whose complaints include ear pain or fullness, and palpate the neck for the presence of adenopathy.

• Perform careful auscultation and percussion of the lungs to exclude the presence of focal findings that would suggest pneumonia.

• In patients with severe symptoms suggestive of sinusitis, the presence of periorbital swelling, conjunctival injection, proptosis, or deficits of the extraocular movements suggests extension of infection beyond the sinuses and requires emergent evaluation.

• In a patient with severe symptoms of pharyngitis, diffuse swelling on one side of the neck or asymmetric tonsillar enlargement with medial displacement suggests a suppurative complication such as a peritonsillar abscess.

Tests for Consideration

• In most patients with acute cough, the absence of any abnormality of vital signs (no fever, tachycardia, or tachypnea) or any focal auscultatory finding on lung examination (focal crackles, bronchial sounds) is sufficient to exclude a diagnosis of pneumonia on clinical grounds. Patients with an abnormality of one of the vital signs listed above or focal findings on auscultation should have a chest radiograph to exclude the possibility of pneumonia.


• In patients with symptoms suggestive of acute sinusitis, radiographs are not recommended routinely, as they will not assist in the differentiation of viral from bacterial infection. CT of the sinuses is reserved for selected situations, such as when extension of infection beyond the sinuses is suspected.


• A rapid antigen detection test (RADT) or culture should be performed to confirm the diagnosis of streptococcal pharyngitis; in adults, a negative result on the RADT is sufficient to exclude the diagnosis of streptococcal pharyngitis.


• Rapid tests are also available for the diagnosis of influenza; however, when influenza is known to be circulating in the community, clinical diagnosis is quite accurate.



Clinical Entities Medical Knowledge

Viral Rhinosinusitis or Common Cold

Viruses responsible for the majority of common colds include rhinoviruses (most common), coronavirus, influenza virus, respiratory syncytial virus, parainfluenza virus, and adenovirus. These viruses are thought to be spread mainly by direct contact with secretions on skin and environmental surfaces; dissemination by infectious secretions in the form of droplet nuclei or larger particles can also occur. The pathogenesis of the common cold is actually poorly understood. Biopsy samples of nasal mucosa from individuals with experimentally induced rhinovirus colds do not reveal evidence of viral cytopathic effect. It is believed that cytokines (interleukins 1, 6, and 8) and other inflammatory mediators play an important role in pathogenesis.


The incubation period of the common cold is short (<3 days). Patients present with sneezing, nasal discharge, and symptoms of nasal obstruction, along with sore or scratchy throat. Mild systemic symptoms, such as low-grade fever, myalgias, and malaise, may be present. Cough may develop during the first few days of illness. Influenza is characterized by the abrupt onset of fever, chills, headache, and myalgia, with the systemic symptoms predominating over the respiratory symptoms.


A diagnosis of the common cold (often referred to as nonspecific URI) is made on clinical grounds. Influenza may be confirmed by RADTs, but (as discussed above) when influenza is known to be circulating in the community, clinical diagnosis is both sensitive and specific. Weekly reports of influenza activity in the United States can be found at http://www.cdc.gov/flu/weekly/index.htm. Many state health departments also post weekly reports of regional influenza activity on their websites.


Treatment of the common cold is symptomatic. Nonsteroidal anti-inflammatory drugs (NSAIDs) can relieve systemic symptoms and sore throat, and may reduce cough. A recent Cochrane review concluded that zinc lozenges reduce the duration and severity of the common cold, but there is currently insufficient data to make recommendations regarding the formulation, dose, and duration of therapy. Two agents available for the treatment of influenza are oseltamivir and zanamivir; both work through inhibition of viral neuraminidase. If used within the first 48 hours of symptoms, these drugs may shorten the duration of illness by 1 to 1.5 days. A greater benefit may be seen in older individuals and those with risk factors for complicated infection. Amantidine and rimantidine are no longer recommended for the treatment of influenza because of a high prevalence of resistance. See Cecil Essentials 98.


Acute Community-Acquired Bacterial Sinusitis

The nasopharynx of healthy individuals may be colonized with bacteria that cause ACABS (e.g., S. pneumoniae); besides S. pneumoniae, Haemophilus influenzae (mainly untypable) and Moraxella catarrhalis are most commonly implicated. Obstruction of the sinus ostia, which may occur as a result of an antecedent VRS, plays an important role in the pathogenesis of ACABS. It is believed that blowing the nose creates a sudden increase in intranasal pressure that forces fluid that may contain these bacteria from the nasal cavity into the sinuses.


Patients present with nasal congestion, purulent nasal discharge, and facial pain/pressure, which may be worsened by leaning forward. There may be maxillary tooth pain in maxillary sinusitis and retro-orbital headache in ethmoid and sphenoid sinusitis; unilateral symptoms are especially suggestive of bacterial sinusitis. Patients may have fever. There is often a history of antecedent symptoms suggestive of VRS, which either fail to improve or begin to improve and then worsen again after 7–10 days of illness.


The diagnosis of ACABS is mainly clinical. Patients with severe symptoms of sinusitis may need antibiotic therapy early in the course of disease; those with mild to moderate symptoms who are not improving by the second week of illness should also be assumed to have a bacterial infection and receive antibiotics. Studies utilizing sinus puncture have been performed to define the microbiology of ACABS; in clinical practice this invasive procedure can be utilized in severely ill patients (especially those with nosocomially acquired sinusitis), but it is not routinely performed. Antibiotics are chosen empirically based on knowledge of the microbiology of bacterial infection of the sinuses. Culture of purulent nasal secretions is not recommended. As discussed above, sinus radiographs cannot distinguish bacterial from viral infections and are not routinely recommended.


Analgesics and decongestants can provide symptomatic relief. Although a number of newer broad-spectrum antimicrobials have shown efficacy in the treatment of ACABS, older agents such as amoxicillin, doxycycline, and TMP-SMX are sufficient for the majority of patients who need antibiotic therapy. See Cecil Essentials 98.


Acute Bronchitis

Infection of the tracheobronchial epithelium leads to acute inflammation and the release of cytokines. The same viruses implicated in the common cold can cause acute bronchitis. The one bacterial pathogen that may be considered in certain patients is Bordetella pertussis (discussed in the Zebra Zone section). Inflammation of the tracheobronchial epithelium leads to airway hyperresponsiveness that manifests as persistent cough and wheezing. The production of purulent sputum reflects inflammation and does not indicate a bacterial infection.


Patients present with cough and may have mild systemic symptoms and wheezing; an antecedent history of symptoms suggestive of the common cold may be present. Auscultation of the chest may reveal diffuse coarse rhonchi and wheezing.


The diagnosis of acute bronchitis is made clinically; some patients with acute cough may require a chest radiograph to exclude the diagnosis of pneumonia, as discussed above under Tests for Consideration.


Inhaled β2-agonists can be beneficial for the treatment of persistent cough and wheezing. The benefit of cough suppressants is questionable. Nine randomized placebo-controlled trials have failed to show a benefit of antibiotic therapy in the treatment of acute bronchitis. See Cecil Essentials 17.



The pathogenesis of viral pharyngitis is similar to that of the common cold. The inflammatory mediator bradykinin is thought to play a key role in the pathogenesis of sore throat. The pathogenesis of streptococcal pharyngitis is not well understood. The organism is often found colonizing the pharynx in asymptomatic individuals. The factors that lead from colonization to infection are not well elucidated, although a number of extracellular factors produced by S. pyogenes, including hemolysins, hyaluronidase, and pyrogenic exotoxins, are probably important in the pathogenesis of disease. The common cold viruses are also implicated as causes of pharyngitis; in addition, patients with Epstein-Barr virus (EBV), cytomegalovirus (CMV), and acute HIV infection can present with pharyngitis accompanied by a mononucleosis-like syndrome. Bacteria are responsible for only 5% to 10% of cases of pharyngitis in adults; the most common is S. pyogenes (group A β-hemolytic streptococcus [GABHS]).


Patients with viral pharyngitis may present with complaints of sore throat along with other symptoms suggestive of URI. In patients with pharyngitis due to GABHS, sore throat and pain in the throat when swallowing are the presenting complaints. Patients may have quite impressive systemic complaints (including fever and chills, abdominal pain, and headache) or may be only mildly ill. On examination, the posterior pharynx will be markedly erythematous with patches of yellow exudates on the tonsils. There may be redness of the tongue with prominence of the papillae (strawberry tongue) and tender enlargement of the cervical lymph nodes.


The presence of the Centor criteria (fever, exudates, tender cervical adenopathy, and absence of cough) can increase the pre-test probability of GABHS pharyngitis; however, the diagnosis should be confirmed by a RADT or a throat culture. Because the prevalence of GABHS infection in adults is lower than in the pediatric population, the diagnosis can be excluded based on a negative RADT.


Analgesics to relieve throat discomfort can be beneficial in viral pharyngitis. For cases confirmed to be secondary to GABHS, penicillin or amoxicillin remain the first-line therapy; a macrolide can be utilized in patients with penicillin allergy. See Cecil Essentials 98.


Otitis Media

The middle ear communicates with the eustachian tube and mastoid air cells, the nasopharynx, and the nares. Any process that interferes with eustachian tube function, such as edema of the mucosa from a viral infection, can predispose to fluid accumulation in the middle ear, and if this fluid contains bacteria (e.g., S. pneumoniae) that can normally be found colonizing the nasopharynx, infection of the middle ear (OM) can ensue. Viruses associated with the common cold may also cause OM; bacterial infections are most frequently caused by S. pneumoniae, followed by H. influenzae and M. catarrhalis.


Adults with OM typically present with pain in the ear, which may be accompanied by decreased hearing, drainage from the ear, and fever. Tinnitus and vertigo may also occur. There may be an antecedent history of URI symptoms.


The tympanic membrane (TM) can be erythematous in any infection of the upper respiratory tract, and this finding alone is insufficient to make a diagnosis of OM. In acute OM, the TM is opaque and may be bulging or retracted. Decreased mobility of the TM with pneumatic otoscopy is consistent with fluid in the middle ear.


A wide variety of antimicrobials could be utilized to treat the bacterial pathogens that commonly cause acute OM; however, amoxicillin remains the first-line choice; amoxicillin-clavulanate and cefuroxime axetil are alternatives. See Cecil Essentials 98.


Oct 3, 2016 | Posted by in MANUAL THERAPIST | Comments Off on Upper Respiratory Tract Infections (Case 48)

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