A

72 y/o woman presented to the ED for swollen and painful leg.
Physical examination shows an erythematous, tender and warm leg.
Probably it is a cellulitis.
In previous post we stressed the US use to increase diagnostic accuracy.

Can WBC or CPR help in the differential diagnoses?
Do they have a role in the decision to admit the patient to the Hospital?

Conclusion

WBC count is not helpful for differential diagnosis, or to determine the route of antibiotics administration, furthermore it has a small weight in the decision to admit a patient to the Hospital.
An elevated CPR is a better indicator to “rule in” but if negative it’s unreliable.

The routine blood investigation in ED takes another beating.

Bibliography

G.Phoenix et al
Diagnosis and management of cellulitis.
BMJ 2012 345: e4955 (published 7 Aug 2012).