Tuesday, November 15, 2016

Group A Steptococcal infection

In morning report, we discussed the case of a man with HIV presenting with sepsis and odynophagia with head and neck lymphadenopathy and symptoms of sinusitis.

We discussed the following learning points:

1.       Head and neck infection: a history of odynophagia, lymphadenopathy and sinusitis is concerning for a head and neck infection. The differential diagnosis would include:
a.       Deep neck space infections such as retropharyngeal abscesses
b.      Peritonsillar abscesses and submandibular space infections (Ludwig’s angina)
c.       Suppurative parotitis
d.      Pharyngitis
e.      Lymphadenitis (including TB lymphadenitis)
f.        Epiglottitis  
g.       Laryngotracheitis
h.      Diphtheria

2.       CD4 count : we discussed that the differential diagnosis will change and be informed by the opportunistic infections that patients with HIV are susceptible to with different CD4 counts:

3.       Meningitis examination: With the history of fever and headache, the question of meningitis comes up. Looking at the JAMA Rational Clinical Examination article on “Does this adult patient have acute meningitis?” from 1999, absence of fever, neck stiffness and altered mental status effectively rules out meningitis. One of the most sensitive maneuvers in the diagnosis of meningitis is jolt accentuation (sensitivity 100%, specificity 54%, positive LR 2.2, negative LR 0); a negative jolt accentuation may essentially exclude meningitis.

In this case, there was no evidence of meningitis on exam (negative jolt accentuation) and swabs and blood cultures were positive for Group A Streptococcus (Sterptococcus pyogenes).  

4.       Group A Streptococcus (GAS) infections:

Types of GAS infection include:
-          Streptococcal tonsillopharyngitis “strep throat”
-          Skin and soft tissue infections
o   Cellulitis
o   Erysipelas
-          Necrotizing fasciitis
-          Myositits
-          Pneumonia
-          Postpartum endometritis
-          Bacteremia associated with toxic shock syndrome

Nonsuppurative Complications of GAS pharyngitis include:
-          Scarlet Fever
-          Rheumatic Fever
-          Glomerulonephritis
-          Toxic Shock Syndrome

Treatment of GAS:
-          GAS is universally sensitive to penicillin and as such penicillin is the first line treatment.
-          Clindamycin is generally used in addition to a beta-lactam in the treatment of invasive GAS has it inhibits protein synthesis, suppressing synthesis of bacterial toxins, and there is evidence that it reduces mortality.
-          For toxic shock syndrome, there is some evidence supporting the adjunctive use of IVIG
-          Don’t forget that early aggressive surgical intervention is key for invasive soft tissue infections, such as necrotizing fasciitis. 

Attia et al. Does this adult patient have acute meningitis? JAMA. 1999;282(2):175-81.
Carapetis et al. Effectiveness of clindamycin and intravenous immunoglobulin, and risk of disease in contacts, in invasive group A streptococcal infections. Clin Infect Dis. 2014;59(3):358.   
Davies et al. Invasive Group A Streptococcal Infections in Ontario, Canada. NEJM. 1996;335:547-54.

Wessels. Streptococcal Pharyngitis. NEJM. 2011;364:648-55.