A 4-year-old boy is brought to the office due to a 1-day fever of 38.4 C (101.1 F) and left-sided neck swelling. His mother says, "He was fine until yesterday, but now his neck is really bothering him." The patient has had no trauma to the area, has not been ill recently, and has no known sick contacts. Vaccinations are up to date. Physical examination shows a red, tender, and fluctuant mass approximately 2 cm in diameter in the left anterior cervical lymph node chain. Dentition and oropharynx are normal. There are no other areas of lymphadenopathy. Which of the following is the most likely infectious etiology?

Question

A 4-year-old boy is brought to the office due to a 1-day fever of 38.4 C (101.1 F) and left-sided neck swelling.  His mother says, "He was fine until yesterday, but now his neck is really bothering him."  The patient has had no trauma to the area, has not been ill recently, and has no known sick contacts.  Vaccinations are up to date.  Physical examination shows a red, tender, and fluctuant mass approximately 2 cm in diameter in the left anterior cervical lymph node chain.  Dentition and oropharynx are normal.  There are no other areas of lymphadenopathy.  Which of the following is the most likely infectious etiology?

Quizplus · Accepted Answer

11ec25c8_d6c0_5b88_bc81_31ae5e425818_MD0003_00 This child has acute, unilateral cervical lymphadenitis, which is most commonly caused by Staphylococcus aureus or Streptococcus pyogenes. Acute cervical lymphadenitis occurs predominantly in children age <5 and frequently involves the submandibular nodes, although any cervical node can be affected. History may reveal a recent upper respiratory infection, but there are often no preceding symptoms. Patients are usually well-appearing and may have fever, as in this boy. Affected lymph nodes are enlarged, markedly tender, warm, and erythematous. Lymphadenitis due to S aureus or S pyogenes often progresses to suppuration and abscess, which are identified by fluctuance on examination, as seen in this patient. The diagnosis is typically clinical. Empiric antibiotic therapy for acute, unilateral cervical lymphadenitis is with clindamycin, which has activity against methicillin-resistant S aureus, as well as S pyogenes. Needle aspiration of a suppurative node can identify the pathogen and further guide antibiotic management. (Choice A) Adenovirus and other viral upper respiratory infections are the most common cause of acute, bilateral cervical lymphadenitis. In addition, adenovirus typically causes marked fever, pharyngitis, and conjunctivitis, findings not seen in this patient. (Choice B) Bartonella henselae causes catscratch disease, which can present with a papular or nodular skin lesion at the site of a cat bite or scratch and is accompanied by ipsilateral lymphadenitis. Unlike S aureus infection, catscratch lymphadenitis has an indolent onset (ie, over several weeks). (Choices C and D) Cytomegalovirus and Epstein-Barr virus cause subacute or chronic, bilateral lymphadenitis in the setting of infectious mononucleosis symptoms (eg, fever, fatigue, pharyngitis). This patient has an acute onset of unilateral cervical lymphadenitis, making a viral cause unlikely. (Choice E) Oral anaerobes (eg, Prevotella spp) are a less common cause of acute cervical lymphadenitis and typically present in a patient with a history of periodontal disease or dental caries. This child's dentition is normal, making a gram-positive bacterium the most likely pathogen. Educational objective: Staphylococcus aureus and Streptococcus pyogenes are the most common causes of acute, unilateral cervical lymphadenitis in children. Affected nodes are enlarged, erythematous, and markedly tender. Suppuration is common. References: Managing cervical lymphadenitis-a total pain in the neck! (http://www.ncbi.nlm.nih.gov/pubmed/25290125) Pediatric cervical lymphadenopathy. (http://www.ncbi.nlm.nih.gov/pubmed/25213279)

A 4-Year-Old Boy Is Brought to the Office Due to a 1-Day