MDCalc

ALT-70 Score for Cellulitis

Predicts likelihood of lower extremity cellulitis over other diagnoses.

Use in adult patients presenting to the ED with a red leg and clinical concern for cellulitis. Do not use if: visible abscess/fluctuance, penetrating trauma, burn, diabetic ulcer, hardware/device, post-operative patient, or recent (within 48 hrs) IV antibiotic use.

Asymmetric
Age ≥70 years
WBC in ED ≥10,000/µL
HR in ED ≥90 bpm

Result:

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Advice

  • Scores 5-7 indicate likely cellulitis (>82.2% likelihood), and patients should receive appropriate therapy. This may vary based on comorbidities or underlying diseases, history of resistant organisms, prior culture data or prior antibiotic use, and/or whether there is a clear trigger or portal of entry.

  • Scores 3-4 indicate uncertainty, and consultation may be appropriate. Dermatology consultation may assist in the evaluation and can help identify alternative etiologies or explanations; if not available, ID consultation may be appropriate. Examples of alternative etiologies include:

    • Vascular inflammation, stasis dermatitis.

    • Inflammatory skin conditions.

    • Alternate infections (e.g. Lyme).

    • Chemotherapeutic reactions.

    • Contact dermatitis.

  • Scores 0-2 suggest patients are unlikely to have true cellulitis (likelihood of pseudocellulitis >83.3%) and should be reassessed to have the differential diagnosis reconsidered. Very common mimickers include:

    • Bilateral redness without tachycardia/leukocytosis in a patient with edema and/or heart failure, suggestive of stasis dermatitis.

    • Pruritic, geometric patch with serous drainage in someone using a topical agent who may have developed allergic contact dermatitis.

Management

  • Patients with true cellulitis should be treated with standard-of-care management, which varies based on their underlying disease state, recent antibiotics or previously documented microbial culture data, and local antibiotic resistant patterns.  This may include oral or IV antibiotics.

  • Patients with pseudocellulitis (mimickers) should be treated appropriately for the identified alternate diagnosis.

Critical Actions

  • Patients with septic physiology may require more immediate attention and aggressive intervention.  

  • Patients with fluctuant lesions/abscesses may require imaging and/or surgical intervention.

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