What does ALT-70 stand for?

Asymmetry (3 points), leukocytosis (1), tachycardia (1), and age 70 years or older (2).

How is ALT-70 interpreted?

In the derivation study, totals 0–2 favored pseudocellulitis, 3–4 were indeterminate, and 5–7 favored true cellulitis. The score must be interpreted in clinical context.

Is ALT-70 a severity score?

No. ALT-70 supports the differential diagnosis of lower-extremity cellulitis versus mimics; it does not grade infection severity or prescribe treatment.

Can ALT-70 be used for children or cellulitis elsewhere on the body?

The model was developed for adults with suspected lower-extremity cellulitis. Performance should not be assumed for children or other anatomical sites.

Does a high score prove cellulitis?

No. Mimics and serious alternative diagnoses still require history, examination, and appropriate testing by a clinician.

ALT-70 Cellulitis Score Calculator

Score asymmetry, leukocytosis, tachycardia, and age 70 or older to calculate the 0–7 ALT-70 prediction score.

ALT-70 Variables

Choose Yes or No for all four variables. This model applies to suspected adult lower-extremity cellulitis.

Asymmetry: unilateral lower-extremity involvement

Leukocytosis: WBC ≥10,000/µL

Tachycardia: heart rate ≥90 beats/min

Age ≥70 years

ALT-70 Total

—

out of 7

Complete all four variables.

Published Categories

0–2Cellulitis unlikely; reassess diagnosis

3–4Indeterminate

5–7Cellulitis likely

Clinical limitation: ALT-70 does not rule out deep vein thrombosis, necrotizing infection, sepsis, or other urgent conditions. It does not select antibiotics or determine admission.

Method: Raff et al., Journal of the American Academy of Dermatology (2017); subsequent external validation published in 2024.

Summary

ALT-70 is a four-variable clinical prediction model designed to help distinguish true lower-extremity cellulitis from pseudocellulitis in adults. The acronym represents asymmetry, leukocytosis, tachycardia, and age 70 years or older. It is a diagnostic-support score, not a cellulitis severity scale, and it does not determine antibiotic choice or treatment setting.

How it works

Record whether lower-extremity involvement is unilateral (asymmetry): 3 points.
Record whether white blood cell count is at least 10,000/µL: 1 point.
Record whether heart rate is at least 90 beats/min: 1 point.
Record whether age is at least 70 years: 2 points.
Add the four components for a total from 0 to 7.
Use the category as one part of a full clinical assessment for adult lower-extremity erythema.

Use cases

Double-check ALT-70 arithmetic at the bedside.
Structure assessment of suspected adult lower-extremity cellulitis.
Identify indeterminate cases that need diagnostic reassessment.
Teach the published ALT-70 variables and thresholds.

Frequently Asked Questions

Last updated: 2026-09-10 · Reviewed by Nham Vu