### Description

Centor et al developed model for diagnosis of streptococcus pharyngitis in an adult. This can help to identify patients who can be treated before culture confirmation is received. The authors are from Medical College of Virginia and Virginia Commonwealth University.

Patient selection: adult (age > 15 years) in the Emergency Department

Parameters:

(1) temperature in °F

(2) anterior cervical lymph nodes

(3) tonsillar exudates

(4) cough

Parameter Finding Points
temperature < 101°F 0
>= 101°F 1
anterior cervical lymph nodes not swollen and tender 0
swollen and tender 1
tonsillar exudates absent 0
present 1
cough (for probability model) present 1
absent 0
cough (for simple score) present 0
absent 1

X =

= (1.04 * (points for exudates)) + (points for cervical LN) - (0.95 * (points for cough)) + (0.89 * (points for fever)) - 2.69

probability of a positive throad culture for Group A beta-hemolytic Streptococcus =

= 1 / (1 + EXP((-1) * X))

A simpler method is to sum the points for the 4 parameters (noting the scoring of cough):

simple score =

= SUM(points for the 4 parameters)

Interpretation:

• minimum simple score: 0

• maximum simple score: 4

• The higher the score the more likely that the patient has Streptococcus pharyngitis.

Simple Score Probability of Positive Culture (Approximate)
0 2.5%
1 6.5%
2 15%
3 32%
4 56%