What is the most common cause of acute pharyngitis/tonsillitis?

Acute pharyngitis and tonsillitis are most commonly caused by viral infections, which account for a significant majority of cases. Viruses like adenovirus, influenza virus, Epstein-Barr virus, and others are prevalent culprits that lead to these conditions. This prevalence stems from the general patterns of upper respiratory infections, where viruses are typically the leading agents due to their ease of transmission and ability to cause inflammation in the throat and tonsils.

While bacterial infections, particularly streptococcal infections, can also cause pharyngitis and tonsillitis, they occur less frequently compared to viral ones. Environmental factors and allergic reactions may contribute to throat discomfort or irritation but are not primary causes of acute pharyngitis or tonsillitis.

Understanding the commonality of viral etiologies helps clinicians guide appropriate evaluations and management strategies, often questioning for the presence of systemic symptoms and considering supportive care, since antibiotics are not warranted in viral infections.