The patient's history alone is rarely a reliable differentiator between viral and bacterial pharyngitis. However, persistence of symptoms beyond 10 days or progressive worsening after the first 5-7 days suggests a bacterial illness. Assessment for group A streptococci warrants special attention. Pharyngeal symptoms of sore or scratchy throat, odynophagia, or dysphagia are common. If the uvula or posterior pharynx is inflamed, the patient may have an uncomfortable feeling of a lump when swallowing. Nasal obstruction may cause mouth breathing, which may result in dry mouth, especially in the morning. Group A streptococcal infections often produce a sudden sore throat. Fever increases the suspicion that infection with group A streptococci is present, as does the absence of cough, rhinorrhea, and conjunctivitis because these are common in viral syndrome.
Nasal symptoms of rhinorrhea, congestion or obstruction of nasal breathing, and sneezing are common early in the course. Clinically significant rhinorrhea is more characteristic of a viral infection rather than a bacterial infection. In viral URI, secretions often evolve from clear to opaque white to green to yellow within 2-3 days of symptom onset. Thus, color and opacity do not reliably distinguish viral from bacterial illness.
Acute viral rhinosinusitis typically has symptom resolution within 10 days, with a peak at 3-6 days. If symptoms last longer than 10 days, or if they improve and worsen within 10 days, acute bacterial rhinosinusitis is more likely.
Pharyngeal erythema is typically marked in adenoviral infection. In contrast, rhinoviral and coronaviral infections are not likely to manifest as severe erythema.
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Cite this: Michael Stuart Bronze. Fast Five Quiz: Upper Respiratory Tract Infections - Medscape - Jan 22, 2021.