A 6-year-old boy is brought to the office with a 10-day history of thick and persistent nasal discharge, nasal congestion, and cough. He has had no associated vomiting, headache, or earache. The patient has mild, persistent asthma for which he uses an inhaled corticosteroid. Temperature is 37.2 C (98.9 F), pulse is 90/min, and respirations are 15/min. Physical examination reveals yellow mucus dripping in the posterior nasopharynx. Tympanic membranes are clear bilaterally. Nasal turbinates are red and swollen. Maxillary sinuses are tender to palpation. Heart sounds are normal and the lungs are clear to auscultation bilaterally. Skin examination shows no rashes. Which of the following organisms is the most likely cause of this patient's condition?

Question

A 6-year-old boy is brought to the office with a 10-day history of thick and persistent nasal discharge, nasal congestion, and cough.  He has had no associated vomiting, headache, or earache.  The patient has mild, persistent asthma for which he uses an inhaled corticosteroid.  Temperature is 37.2 C (98.9 F), pulse is 90/min, and respirations are 15/min.  Physical examination reveals yellow mucus dripping in the posterior nasopharynx.  Tympanic membranes are clear bilaterally.  Nasal turbinates are red and swollen.  Maxillary sinuses are tender to palpation.  Heart sounds are normal and the lungs are clear to auscultation bilaterally.  Skin examination shows no rashes.  Which of the following organisms is the most likely cause of this patient's condition?

Quizplus · Accepted Answer

11ec25c8_d6d3_e2a7_bc81_5bb29843e556_MD0003_00 The duration of this patient's symptoms is consistent with acute bacterial rhinosinusitis (ABRS). Although the paranasal sinuses are not fully developed in children, the ethmoid and maxillary sinuses are present at birth and rapidly expand in the first few years of life. Inflammation within the sinus cavity (eg, viral upper respiratory infection) can impair mucous drainage and lead to secondary bacterial infection. Nontypeable Haemophilus influenzae (~40%-50%), Streptococcus pneumoniae (~20%-25%), and Moraxella catarrhalis (~25%) are the most commonly implicated bacteria. Since the advent of the 13-valent pneumococcal vaccine, S pneumoniae infection has become less prevalent. The most common presentation of ABRS is nasal discharge and cough lasting ≥10 days without improvement. In contrast, viral rhinosinusitis generally improves by days 7-10. Fever may be present in ABRS but is not required for diagnosis. In addition, sinus tenderness is rare in young children but often found in adults with ABRS. Patients with asthma may experience exacerbations (eg, wheezing, coughing) triggered by concurrent upper respiratory infection. Treatment is amoxicillin ± clavulanate if symptoms are severe (eg, high fever) or worsening. Patients with a milder course (persistent but not worsening symptoms) may be observed or treated with oral antibiotics. (Choices A and D) Fungal pathogens (eg, Aspergillus fumigatus, Rhizopus arrhizus) can cause life-threatening sinusitis in patients with impaired host defenses (eg, poorly controlled diabetes mellitus, malignancy). Epistaxis, turbinate destruction, palatal eschars, and maxillary cyanosis raise suspicion for fungal infection. This patient does not have these findings, making fungal pathogens unlikely. (Choice C) Pseudomonas aeruginosa causes sinusitis in immunocompromised patients and patients with cystic fibrosis. This patient does not have risk factors for P aeruginosa. (Choice E) Staphylococcus aureus may be seen in chronic sinusitis (sinus inflammation for >12 weeks) but is rarely a cause of ABRS in children. (Choice F) Streptococcus pyogenes typically causes pharyngitis without cough or nasal discharge. Group A Streptococcus rarely causes sinus infections. Educational objective: Nontypeable Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis are the most common bacterial causes of acute bacterial rhinosinusitis, which commonly presents with ≥10 days of persistent nasal discharge and cough. References: IDSA clinical practice guideline for acute bacterial rhinosinusitis in children and adults. (http://www.ncbi.nlm.nih.gov/pubmed/22438350) Clinical practice guideline for the diagnosis and management of acute bacterial sinusitis in children aged 1 to 18 years. (http://www.ncbi.nlm.nih.gov/pubmed/23796742)

A 6-Year-Old Boy Is Brought to the Office with a 10-Day