Which pathogens are most commonly responsible for unilateral cervical adenitis?

Unilateral cervical adenitis, characterized by swelling of the lymph nodes on one side of the neck, is often caused by bacterial infections. Staphylococcus aureus and Streptococcus pyogenes (Group A Streptococcus) are particularly common culprits in this scenario. These pathogens are known to cause localized infections, which can lead to lymphadenopathy due to the body's immune response that tries to fight off the infection.

Staphylococcus aureus is a prevalent skin pathogen that can lead to abscess formation and localized infection, while Streptococcus pyogenes can cause pharyngitis, which may also result in reactive lymphadenitis. The presence of these bacteria often leads to unilateral symptoms, making them the most likely pathogens responsible for this condition.

Other potential pathogens listed, such as adenovirus and EBV, are more associated with viral infections that typically do not cause the same purulent, unilateral lymphadenopathy seen with bacterial infections. Similarly, Mycobacterium and anaerobic bacteria, while they do cause lymphadenopathy, tend to be associated with different clinical presentations and risk factors. Thus, the combination of Staphylococcus and Streptococcus pyogenes is the most common etiology for unilateral cervical adenitis, confirming the selection