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a. Rhinovirus Make your selection before scrolling beyond this point Answer: Common viral causes of acute pharyngitis include rhinovirus (which is associated with mild pharyngeal inflammation), adenovirus (which presents with severe sore throat with fever, pharyngeal erythema and exudate), influenza A and B viruses, and other respiratory viruses. Other viral etiologies include Ebstein-Barr virus (EBV), cytomegalovirus, coxsackievirus, herpes simplex virus (I/II), and HIV. Among bacterial pathogens, Group A beta-hemolytic streptococci (S. pyogenes) is the most common cause of acute pharyngitis, responsible for 10-15% of all cases. Streptococcal pharyngitis typically presents with acute onset of sore throat, fever, chills without rigors, tender submandibular adenopathy, and pharyngeal erythema with punctate or confluent exudate; milder cases with few symptoms/findings also occur. In addition to viruses and bacteria, acute pharyngitis may also be caused by Mycoplasma pneumoniae or Chlamydia pneumoniae; M. pneumoniae is responsible for up to 10% of cases in adults, and is often accompanied by otitis and/or bullous myringitis. Mouth anaerobes do not commonly cause acute pharyngitis. (Answer: a, b, d) 2. Which of the following statements about Group A streptococcal pharyngitis are true? a. The absence of a tonsillar
exudate excludes the diagnosis Make your selection before scrolling beyond this point Answer: Although streptococcal pharyngitis commonly manifests an erythematous pharynx with punctate or confluent exudates on physical examination, mild cases may occur without pharyngeal exudate. Even without treatment, sore throat, fever, and other manifestations usually resolve spontaneously in 3-4 days; however, antibiotics may prevent acute rheumatic fever and suppurative complications such as peritonsillar abscess. The risk of complications depend on properties of the infecting strain: non-suppurative complications include acute rheumatic fever, post-strep glomerulonephritis, and streptococcal toxic shock syndrome; bacteremia, scarlet fever, and suppurative head and neck infections may also occur. (Answer: c, d) 3. Acceptable forms of treatment for Group A streptococcal pharyngitis include: a. Amoxicillin 1 gm (PO) q8h x 7-10
days Make your selection before scrolling beyond this point Answer: All are acceptable forms of therapy. 4. Correct statement about post-streptococcal acute rheumatic fever (ARF) and acute glomerulonephritis (AGN) include: a. Early antibiotic treatment of
streptococcal pharyngitis prevents ARF and AGN Make your selection before scrolling beyond this point Answer: Early antibiotic treatment of streptococcal pharyngitis prevents ARF, but AGN may still occur. ARF and AGN may complicate streptococcal pharyngitis, but only AGN is associated with streptococcal skin infections. ARF is an inflammatory condition following streptococcal pharyngitis and usually manifests after a latency period of 1-5 weeks. Major manifestations include polyarthritis (most common), pancarditis (pericarditis, myocarditis, endocarditis), chorea, erythema marginatum and/or subcutaneous nodules; minor manifestations include arthralgia, fever, and elevated sedimentation rate, C-reactive protein and other acute-phase reactants. Supporting evidence of an antecedent Group A streptococcal infection includes an elevated/rising streptococcal antibody (ASO) titer. Carditis may be asymptomatic during the acute phase of rheumatic fever, only to present 20-30 years later with mitral and/or aortic stenosis/regurgitation. Treatment of ARF consists of anti-inflammatory agents (high-dose aspirin; steroids are usually reserved for patients with heart failure who are unresponsive and/or unable to tolerate aspirin); antibiotic prophylaxis (e.g., benazthine penicilllin 1.2 mu IM monthly) is recommended into adulthood to prevent recurrent attacks, which are much more common in patients prior episodes of ARF. Post-streptococcal AGN can present as acute nephritis or as isolated hematuria and proteinuria, usually after a latency period of 10 days to several weeks after pharyngitis. By the time patients present with symptoms (e.g. hypertension), throat cultures may be negative for streptococcus, although streptococcal antibody titers are elevated and serum complement levels are depressed in > 90% of patients. AGN is typically a self-limited disease; renal function and blood pressure usually return to normal within weeks, and hematuria and proteinuria resolve in weeks to months. (Answer: c) 5. Correct statements about acute epiglottitis include: a. Usual pathogens include
Streptococcus pneumoniae or Hemophilus influenzae Make your selection before scrolling beyond this point Answer: Early diagnosis and management are critical in epiglottis, due to the risk for acute upper airway obstruction, retropharyngeal/epiglottic abscess formation, bacteremia, pneumonia, meningitis and other systemic complications in untreated infection. Mortality rates up to 30% have been reported in adults. Antibiotics active against H. influenzae and S. pneumoniae (usual epiglottitis pathogens) are mandatory: recommended IV therapy consists of ceftriaxone or ceftizoxime; meropenem or imipenem may also be used. Patients responding to IV therapy can be switched to PO therapy with a quinolone or cefprozil to complete a total of two weeks therapy. Prophylactic endotracheal (nasotracheal) intubation is recommended in children; adults require careful airway monitoring for possible intubation as well. Culture of the epiglottis is contraindicated due to the increased risk of upper airway obstruction. (Answer: all are correct)
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