The incidence of colds peaks in colder months, typically between September and March.
Purulent nasal discharge, otitis, high fever, or other severe systemic symptoms suggest complication of infection or a different cause of infection, like influenza.
Laboratory Findings
Specific diagnostic testing is rarely needed but may be attempted for severe or complicated infection. Nasopharyngeal swabs or washings are recommended for diagnostic testing, if indicated.
Direct antigen testing: Available for several viral pathogens, including influenza viruses and RSV.
Viral culture: High sensitivity for correctly collected and transported specimens.
Molecular tests: Available for detection of a very broad range of viral respiratory tract pathogens.
Serology: Not useful.
PHARYNGITIS
Definitions
Acute pharyngitis, inflammation of the posterior pharyngeal and tonsillar tissues, is a common clinical complaint, especially in children. Most episodes of acute pharyngitis are relatively mild, self-limited infectious diseases, caused by common upper respiratory tract pathogens. The etiology varies somewhat by the age of the patient and season. In general, however, viral infection is the most common cause of acute pharyngitis, both in children and adults. Detection of group A beta-hemolytic streptococcus (
Streptococcus pyogenes
) is the focus of most diagnostic testing, however, because of the risk of poststreptococcal acute RF and GN. Specific diagnosis may also guide the appropriate use, or nonuse, of antibiotics. Acute pharyngitis must be distinguished from other serious infections of the head and neck, like epiglottitis, peritonsillar abscess, and submandibular abscess. Severe symptoms and sepsis, difficulty swallowing and drooling, neck swelling and other signs suggest other sites of primary infection or local, suppurative complications of bacterial pharyngitis.
Etiology
Viral Disease
Acute respiratory infection is the cause of significant morbidity and mortality throughout the world. Viruses are the cause of most of these infections, and children are primarily affected. There is a clear seasonal pattern for most of the viral pathogens, especially in temperate climates where incidence peaks during the winter months. There may be differences in clinical presentations depending on the agent, age of the patient, underlying health, and other factors.
Most nasopharyngeal viral infections present as the “common cold,” manifested by mild symptoms like rhinitis, nasal congestion, sneezing, and runny nose. Mild pharyngitis and “ticklish” cough may be reported. Fever, headache, and malaise, if present, are usually mild. Most upper respiratory tract viral infections resolve completely after 7–10 days. Complications are uncommon, including otitis media, sinusitis, and exacerbations of chronic pulmonary disease.
