Walsh et al developed a discriminant function and a flow diagram to determine the chances of a sore throat in an adult being Streptococcal pharyngitis. The authors are from Dartmouth Medical School and Albert Einstein College of Medicine.
Patient selection: adult with sore throat
Parameters:
(1) oral temperature in °C
(2) recent exposure to someone with a streptococcal infection
(3) recent cough
(4) pharyngeal exudates
(5) enlarged or tender cervical lymph nodes
|
Parameter |
Finding |
Points |
|
temperature in °F |
temperature < 97°F |
0 |
|
|
temperature >= 97°F |
3 * ((temp) - 97) |
|
recent exposure |
no |
0 |
|
|
yes |
17 |
|
recent cough |
no |
0 |
|
|
yes |
-7 |
|
pharyngeal exudates |
no |
0 |
|
|
yes |
6 |
|
enlarged/tender nodes |
no |
0 |
|
|
yes |
11 |
where:
• Figure 3 states that 3 points is assigned for every degree of 36.1°C (97°F). The example on page 1495 assigns 3 points for the difference in degrees Fahrenheit.
discriminant score =
= SUM(points for all 5 parameters)
Interpretation:
• minimum score: -7
• maximum score: 58 (depends on temperature)
• A score < 10 is low risk with a 4% chance of having a positive throat culture.
The flow diagram (Figure 1) can be rearranged into a series of rules.
|
Findings |
Risk |
|
(enlarged and tender lymph nodes) AND (pharyngeal exudates) |
high risk (23-28%) |
|
(enlarged and tender lymph nodes) AND (recent exposure to streptococcal infection) |
high risk (23-28%) |
|
(recent cough) AND (oral temperature < 101°F) |
low risk (3-4%) |
|
all others |
moderate risk (12-15%) |
Specialty: Infectious Diseases, Pedatrics, Otolaryngology
ICD-10: ,
