ALT-70 Score Calculator for Lower Extremity Cellulitis
Predicts the likelihood of lower extremity cellulitis compared with other diagnoses. This tool is for clinical decision support only and should not replace clinician assessment.
Select “Yes” if one lower limb is affected more than the other.
Enter WBC in ×10⁹/L. Leukocytosis is counted if WBC ≥10.0 ×10⁹/L,
equivalent to ≥10,000/µL. Adds 1 point.
Tachycardia is counted if heart rate ≥90 beats/min. Adds 1 point.
Age ≥70 years adds 2 points.
Clinical note: The ALT-70 score is an adjunct for suspected
lower extremity cellulitis. Consider alternative diagnoses such as venous stasis
dermatitis, lipodermatosclerosis, gout, deep vein thrombosis, contact dermatitis,
and other mimics when the score is low or indeterminate.
References
- Raff AB, Weng QY, Cohen JM, et al. A predictive model for diagnosis of lower extremity cellulitis: a cross-sectional study. Journal of the American Academy of Dermatology. 2017;76(4):618-625.e2.
- Li DG, Dewan AK, Xia FD, et al. The ALT-70 predictive model outperforms thermal imaging for the diagnosis of lower extremity cellulitis: a prospective evaluation. Journal of the American Academy of Dermatology. 2018;79(6):1076-1080.e1.
- Singer S, Weng QY, Raff AB, et al. The ALT-70 cellulitis model maintains predictive value at 24 and 48 hours after presentation. Journal of the American Academy of Dermatology. 2019;81(6):1252-1256.
- Pulia MS, et al. Validation of Thermal Imaging and the ALT-70 Prediction Model to Differentiate Cellulitis From Pseudocellulitis. JAMA Dermatology. 2024.
