Respiratory Problems: Introduction
Respiratory infections and chronic lung diseases are among the most common reasons that patients consult primary care physicians. Most of the respiratory problems encountered by primary care physicians are acute, with the majority comprising respiratory infections, exacerbations of asthma, chronic obstructive pulmonary diseases (COPDs), and pulmonary embolism (PE).
Upper Respiratory Tract Infections
- Sore throat, congestion, low-grade fever, mild myalgias, and fatigue.
- Symptoms lasting for 12-14 days.
Although colds are mild, tend to get better on their own, and are of short duration, they are a leading cause of sickness and of industrial and school absenteeism. Each year, colds account for 170 million days of restricted activity, 23 million days of school absence, and 18 million days of work absence.
Most colds are caused by viruses. Rhinoviruses are the most common type of virus and are found in slightly more than half of all patients. Coronaviruses are the second most common cause. In rare instances (0.05% of all cases), bacteria can be cultured from individuals with cold symptoms. It is not clear if these bacteria cause the cold, are secondary infectious agents, or are simply colonizers. Bacterial pathogens that have been identified include Chlamydia pneumoniae, Haemophilus influenzae, Streptococcus pneumoniae, and Mycoplasma pneumoniae.
The mechanisms of transmission suggest that colds can be spread through contact with inanimate surfaces, but the primary transmission appears to be via hand-to-hand contact. The beneficial effects of removing viruses from the hands are supported by observations that absences due to colds among children in day-care or school settings have been reduced through the use of antiseptic hand wipes throughout the day.
Colds generally last 12-14 days. Telling patients that colds last no longer than a week underestimates the actual natural history of an uncomplicated viral respiratory tract infection and leads patients to believe that symptoms that persist beyond a week are not normal. When the symptoms of congestion persist longer than 2 weeks, consideration should be given to other causes of chronic congestion (Table 27-1).
Common cold |
Sinusitis |
Viral |
Allergic |
Bacterial |
Fungal |
Seasonal allergic rhinitis |
Vasomotor rhinitis |
Rhinitis secondary to α-agonist withdrawal |
Drug-induced rhinitis (eg, cocaine) |
Nasal foreign body |
Symptoms of colds include sore throat, congestion, low-grade fever, and mild myalgias and fatigue. In general, early in the development of a cold the discharge is clear. As more inflammation develops, the discharge takes on some coloration. A yellow, green, or brown-tinted nasal discharge is an indicator of inflammation, not secondary bacterial infection. Discolored nasal discharge raises the likelihood of sinusitis, but only if other predictors of sinusitis are present. In addition, several studies have shown that patients with discolored discharge respond to antibiotics no better than they respond to placebos.
Primary complications from upper respiratory tract infection are otitis media and sinusitis. These complications develop from obstruction of the eustachian tube or sinus ostia from nasal passage edema. Although treatment of these infections with antibiotics is common, the vast majority of infections clear without antibiotic therapy.
One misconception is that using antibiotics during the acute phase of a cold can prevent these complications. Evidence shows that taking antibiotics during a cold does not reduce the incidence of sinusitis or otitis media.
The differential diagnosis of colds includes complications of the cold such as sinusitis or otitis media, acute bronchitis, and noninfectious rhinitis. Influenza shares many of the symptoms of a common cold, but generally patients have a much higher fever, myalgias, and more intense fatigue.
Despite the widespread recognition that viruses cause common colds, several studies have shown that patients with the common cold who are seen in physicians’ offices are often treated with antibiotics. The prescribing of antibiotics for colds occurs more often in adults than children. Although this practice appears to have declined in adults, the use of broad-spectrum antibiotics for colds is still common in children. The need to reduce the use of antibiotics for viral conditions has important ramifications on community-wide drug resistance; in areas in which prescribing antibiotics for respiratory infections has been curtailed, reversals in antibiotic drug resistance have been observed.
Currently, the most effective symptomatic treatments are over-the-counter decongestants, the most popular of which include pseudoephedrine hydrochloride and topically applied vasoconstrictors. These agents produce short-term symptomatic relief. However, patients must be warned to use topical agents cautiously because prolonged use is associated with rebound edema of the nasal mucosa (rhinitis medicamentosa).
Several over-the-counter medications contain a mix of decongestants, cough suppressants, and pain relievers. Again, the use of these preparations will not cure the common cold but will provide symptomatic relief.
Antihistamines, with a few exceptions, have not been shown to be effective treatments. Zinc gluconate lozenges are available without a prescription, but a meta-analysis of 15 previous studies on zinc concluded that zinc lozenges were not effective in reducing the duration of cold symptoms.
Some herbal remedies are useful for treatment of the common cold. Echinacea, also known as the American coneflower, has been purported to reduce the duration of the common cold by stimulating the immune system; however, evidence for its efficacy is mixed. Echinacea should be used only for 2-3 weeks to avoid liver damage and other possible side effects that have been reported during long-term use of this herb. Ephedra, also known as ma huang, has decongestant properties that make it similar to pseudoephedrine. Ephedra is more likely than pseudoephedrine to cause increased blood pressure tachyarrhythmia. This is especially true if used in conjunction with caffeine.
Other herbal preparations that have been touted as remedies for the common cold include goldenseal, yarrow, eyebright, and elderflower. However, no systematic evidence supports the use of these herbs in treating the common cold.
- “Double-sickening” phenomenon.
- Maxillary toothache and purulent nasal discharge.
- Poor response to decongestants.
- History of discolored nasal discharge.
Sinusitis is most often a complication of upper respiratory viral infections, so the incidence peaks in the winter cold season. Medical conditions that may increase the risk for sinusitis include cystic fibrosis, asthma, immunosuppression, and allergic rhinitis. Cigarette smoking may also increase the risk of bacterial sinusitis during a cold because of reduced mucociliary clearance.
Most cases of acute sinusitis are caused by viral infection. The inflammation associated with viral infection clears without additional therapy. Bacterial superinfection of upper respiratory infections (URIs) is rare and occurs in only 0.5%-1% of colds. Fungal sinusitis is very rare and usually occurs in immunosuppressed individuals or those with diabetes mellitus.
Acute sinusitis has considerable overlap in its constellation of signs and symptoms with URIs. One-half to two-thirds of patients with sinus symptoms seen in primary care are unlikely to have sinusitis. URIs are often precursors of sinusitis and at some point symptoms from each condition may overlap. Sinus inflammation from a URI without bacterial infection is also common.
The signs and symptoms that increase the likelihood that the patient has acute sinusitis are a “double-sickening” phenomenon (whereby the patient seems to improve following the URI and then deteriorates), maxillary toothache, purulent nasal discharge, poor response to decongestants, and a history of discolored nasal discharge.
Antibiotics are commonly prescribed for adult patients who present with complaints consistent with acute sinusitis. The effectiveness of antibiotics is unclear. If an antibiotic is used, evidence with trimethoprim-sulfamethoxazole suggests that short-duration treatment (eg, 3 days) is as effective as longer treatment. Further, a meta-analysis indicates that narrow-spectrum agents are as effective as broad-spectrum agents.
- High Fever.
- Extreme fatigue.
- Myalgias.
Diagnosis, treatment, and prevention of influenza in children are reviewed extensively in Chap. 5.
Although most cases of the flu are mild and usually resolve without medical treatment within 2 weeks, some will develop complications. Currently, three types of viruses causing influenza have been identified in the United States: A, B, and C. Seasonal epidemics from influenza A and B are seen every winter. Type C influenza usually causes a mild respiratory illness and is not responsible for epidemics. If a new strain emerges and infects a population, an influenza pandemic can result.
Influenza A is identified by two proteins on the virus surface: a hemagglutinin (H) and a neuraminidase (N). These proteins result in 16 different H subtypes and 9 different N subtypes. The A form of influenza can be further divided into strains. The two subtypes of influenza A found in humans currently are A(H1N1) and A(H3N2). In 2009, an influenza pandemic occurred when a very different strain of influenza A(N1H1) developed in humans. The influenza B is broken down by different strain, but not by subtypes.
The most effective prevention is vaccination against influenza. The seasonal flu vaccination contains the regular influenza A’s (H1N1/H3N2) and influenza B and is based on the previous year experience of the viruses seen during that season. However, new strains would not be included in the already manufactured vaccine. With the emergence of the 2009 H1N1 virus, a new vaccination was developed for the new strain. People were encouraged to receive both influenza vaccinations. Influenza vaccinations require annual dosing. A complete listing of who should be immunized can be found on the Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP) web site and others.
The spread of influenza is from person to person by sneezing or coughing. Therefore, everyday care to stay healthy can help prevent contracting the flu and/or spreading the flu to others. Simple steps, such as covering nose and mouth when sneezing or coughing with a tissue; avoiding touching mouth, nose, and eyes if sick; washing hands frequently with soap or germicide solution; and staying home if sick to avoid others, may help prevent the spread of influenza.
The flu can last from 3 days to 2 weeks. Mild cases may be thought to have the common cold and receive no medical treatment. Symptoms include high fever, extreme fatigue, and myalgias. Other symptoms associated with the flu include sore throat, rhinorrhea, cough, headache, and chills. Some people experience nausea, vomiting, and diarrhea.
Complications can lead to hospitalization and even death. These complications include, but are not limited to, otitis media, sinusitis, acute bronchitis, and pneumonia. Exacerbations of chronic illnesses such as asthma, congestive heart failure, and chronic obstructive lung disease are further complications of the flu.
One must consider other viruses, such as the common cold viruses which have many of the same symptoms in less severity.
People who develop symptoms of the flu should seek medical treatment as soon as possible, especially those in the high-risk group, as shown in Table 27-2. If treatment with antivirals is begun within 48 hours of becoming ill, the patient gets the greatest benefit. These benefits include shortening the illness by at least 24 hours, preventing serious complications, and decreasing the likelihood of spreading the disease to others. Treatment with oseltamivir or zanamivir is effective against all forms of human influenza, including A(H1N1)/(H3N2), 2009 A(H1N1), and B. Two older medications, amantadine and rimantadine, remain susceptible to influenza A but not to B. The CDC recommends the use of oseltamivir or zanamivir at this time, due to the emergence of the new strain of A(N1H1). Treatment guidelines differ for age groups and high-risk groups. Therefore, it is important when considering treatment options to refer to the Physician’s Desk Reference (PDR) to ensure appropriate treatment is given. Symptomatic treatment can be given with antipyretic for the fever and anti-inflammatory for pain and myalgias.
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Centers for Disease Control and Prevention (CDC), Advisory Committee on Immunization Practices (ACIP): Recommended Adult Immunization ScheduleUnited States 2010, February 9, 2010, http://www.cdc.gov/vaccines/pubs/ACIP-list.htm.
Lower Respiratory Tract Infections
- Cough lasting more than 3 weeks.
- Fever, constitutional symptoms, and a productive cough.
Viral infection is the primary cause of most episodes of acute bronchitis. A wide variety of viruses has been shown to cause acute bronchitis, including influenza, rhinovirus, adenovirus, coronavirus, parainfluenza, and respiratory syncytial virus. Nonviral pathogens, including M pneumoniae and C pneumoniae (TWAR), have also been identified as causes.
The etiologic role of bacteria such as H influenzae and S pneumoniae in acute bronchitis is unclear because these bacteria are common upper respiratory tract flora. Sputum cultures for acute bronchitis are therefore difficult to evaluate because it is unclear whether the sputum has been contaminated by pathogens colonizing the nasopharynx.
Patients with acute bronchitis may have a cough for a significant time. Although the duration of the condition is variable, one study showed that 50% of patients had a cough for more than 3 weeks and 25% for more than 4 weeks. Other causes of chronic cough are shown in Table 27-3.
Pulmonary causes |
Infectious |
Postobstructive pneumonia |
Tuberculosis |
Pneumocystis jiroveci (formerly, Pneumocystis carinii) |
Bronchiectasis |
Lung abscess |
Noninfectious |
Asthma |
Chronic bronchitis |
Allergic aspergillosis |
Bronchogenic neoplasms |
Sarcoidosis |
Pulmonary fibrosis |
Chemical or smoke inhalation |
Cardiovascular causes |
Congestive heart failure/pulmonary edema |
Enlargement of left atrium |
Gastrointestinal tract |
Reflux esophagitis |
Other causes |
Medications, especially angiotensin-converting enzyme (ACE) inhibitors |
Psychogenic cough |
Foreign body aspiration |
Both acute bronchitis and pneumonia can present with fever, constitutional symptoms, and a productive cough. Although patients with pneumonia often have rales, this finding is neither sensitive nor specific for the illness. When pneumonia is suspected on the basis of the presence of a high fever, constitutional symptoms, severe dyspnea, and certain physical findings or risk factors, a chest radiograph should be obtained to confirm the diagnosis.
Asthma and allergic bronchospastic disorders can mimic the productive cough of acute bronchitis. When obstructive symptoms are not obvious, mild asthma may be diagnosed as acute bronchitis. Further, because respiratory infections can trigger bronchospasm in asthma, patients with asthma that occurs only in the presence of respiratory infections resemble patients with acute bronchitis.
Finally, nonpulmonary causes of cough should enter the differential diagnosis. In older patients, congestive heart failure may cause cough, shortness of breath, and wheezing. Reflux esophagitis with chronic aspiration can cause bronchial inflammation with cough and wheezing. Bronchogenic tumors may produce a cough and obstructive symptoms.
Clinical trials of the effectiveness of antibiotics in treating acute bronchitis have had mixed results. Meta-analyses indicated that the benefits of antibiotics in a general population are marginal and should be weighed against the impact of excessive use of antibiotics on the development of antibiotic resistance.
Data from clinical trials suggest that bronchodilators may provide effective symptomatic relief to patients with acute bronchitis. Treatment with bronchodilators demonstrated significant relief of symptoms, including faster resolution of cough and return to work. The effect of albuterol in a population of patients with undifferentiated cough was evaluated and no beneficial effect was found. Because a variety of conditions presents with cough, there may have been some misclassification in generalizing this finding to acute bronchitis.
- Fever and cough (productive or nonproductive).
- Tachypnea.
- Rales or crackles.
- Positive chest radiograph.
