Tag Archives: Strep

Sore throat

Tonsillitis, pharyngitis.  See SIGN guideline.

“Doughnut lesions” – multiple small erythematous papules with clear centres – associated with group A streptococcus.

See also pharyngitis treatment.

FeverPAIN scoring system – possibly better than Centor at avoiding antibiotics. For primary care settings, children over 3 and adults.

  • Fever in past 24hrs
  • Purulent tonsils
  • Attends rapidly (ie symptoms <=3 days)
  • Severe tonsil Inflammation
  • No cough/coryza

3 points gives 40-50% risk of strep, so treat at 4 points, consider delayed antibiotics for 3 points.  Not for under 3s, and beware worsening after 3 days which might indicate more severe infection. [PRISM study 2014]

Centor and McIsaac scores to predict group A streptococcal pharyngitis.  One point for each of the following:

  • fever,
  • absence of cough,
  • presence of tonsillar exudates, and
  • swollen, tender anterior cervical nodes [my emphasis].

Centor score is sum (0-4). The McIsaac score (1998) is an adjustment of +1 to account for the increased incidence of GAS in children <15yr and -1 for decreased incidence in those 45+ years.   CDC advises treat empirically at score 3+ or at score 2 if rapid testing positive.

Original studies used small samples, but national US study confirmed validity in 65 000 patients aged 3-14yrs presenting to primary care.  For children, GAS positive rates were:

  • 14% for McIsaac 1
  • 23% for 2
  • 37% for 3
  • 55% for 4

AUC was 0.71 for McIsaac score across all ages.

Fine and Nizet, Archives of Internal Medicine. 172(11):847-52, 2012 Jun 11. PMID  22566485

Other clinical decision rules include:

  • the WHO rule (purulent oropharyngeal exudate and tender enlarged anterior cervical lymph nodes = bacterial pharyngitis);
  • the Abu Reesh rule (purulent oropharyngeal exudate or tender enlarged anterior cervical lymph nodes = bacterial pharyngitis); v low specificity of course
  • the Steinhoff rule (absence of rash, absence of moderate or severe rhinitis, presence of tender enlarged anterior cervical lymph nodes).

Rapid antigen test performs better, 85% sensitivity (similar to Abu Reesh rule) but much better PPV (48%).