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Respiratory infections and chronic lung diseases are among the most common reasons why patients consult primary care physicians. Most 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).




  • Sore throat, congestion, low-grade fever, mild myalgias, and fatigue.

  • Symptoms lasting for 12–14 days.

General Considerations

Although colds are mild, self-limiting, and short in duration, they are a leading cause of sickness in 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. Rarely (0.05% of all cases) can bacteria be cultured from individuals with cold symptoms. It is not clear whether 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 of children have been reduced through the use of antiseptic hand wipes throughout the day at school or daycare.

Clinical Findings

Colds generally last 12–14 days. Reassurance and education to patients reduces misconceptions that symptoms lasting >1 week are abnormal. When the symptoms of congestion persist longer than 2 weeks, other causes of chronic congestion should be considered (Table 28-1).

Table 28–1.Differential diagnosis for congestion and rhinorrhea.

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. Therefore education to patients and reassurance is needed, and not reflexive antibiotic prescriptions, which some patients ultimately desire.



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