Spot the Imposter: A New Diagnostic Model for Cellulitis
Despite the frequency with which it affects patients, cellulitis can be difficult to diagnose because symptoms mimic other skin conditions. More than 30% of patients diagnosed with cellulitis actually have a condition known as pseudocellulitis; misdiagnosis delays effective care, results in unnecessary exposure to antibiotics, and hospitalization, which carries further risks to patient health.
A recent study reported efforts to create a model for predicting the likelihood of cellulitis versus pseudocellulitis among patients being admitted to the hospital through the emergency department (ED). Using a retrospective chart review of patients diagnosed with cellulitis, the authors were able to identify four characteristics that were predictive of lower extremity cellulitis: asymmetry (unilateral leg involvement), leukocytosis, tachycardia, and age over 70 years. These criteria were used to develop a scoring system named the ALT-70. This quick and clear tool helps distinguish patients with true cellulitis.
In the studied cohort, patients that received an ALT-70 cellulitis score below 3 had an 83.3% likelihood of pseudocellulitis, while patients with scores above 4 had an 82.2% likelihood of true cellulitis. Those in the 3-4 range fell in an intermediate zone and a dermatology consultation would help with determining best course of treatment. The authors note that while the scoring system has not been validated prospectively, the ALT-70 scoring algorithm offers a simple, objective, and rapid tool to help distinguish cellulitis from its mimickers.
They emphasize that despite the limitations, a clear scoring tool is necessary to reduce the costs and increased patient care associated with misdiagnosis of cellulitis. The lack of a definitive diagnostic algorithm for cellulitis and clear biomarkers point to the need for clinical decision support and evidence-based guidance. They hope that their model will be a step towards an objective standard for early evaluation of cellulitis.
Byline: Martha L. Sikes, MS, RPh, PA-C
Posted: May 22, 2017
Adapted from the original article.
[Image: DermNet New Zealand]