Free MDSteps Library Preview
You’ve viewed 0 of 5 free topics.
Unlock Unlimited Articles - Free for 3 Days
MDSteps- USMLE® Reference Library

Community-Acquired Cellulitis — MRSA Considerations, Lymphatic Care, and Source Control

System: Internal Medicine • Reviewed: Sep 2, 2025 • Step 1Step 2Step 3

Synopsis:

Erythema, warmth, and tenderness of skin/subcutaneous tissue. Differentiate purulent vs nonpurulent cellulitis; drain abscesses and choose antibiotics considering MRSA risk. Address risk factors (tinea pedis, edema, venous stasis) to prevent recurrence.

Key Points

  • Use the highest‑yield diagnostic test early; do not let testing delay time‑critical therapy.
  • Set objective targets and reassess frequently.
  • Plan definitive source control or disease‑specific therapy when indicated; document follow‑up and patient education.

Algorithm

  1. Determine purulent vs nonpurulent; drain abscesses.
  2. Start empiric antibiotics tailored to phenotype and risk factors; escalate for systemic toxicity.
  3. Address predisposing conditions; provide recurrence prevention plan.

Clinical Synopsis & Reasoning

Erythema, warmth, and tenderness of skin/subcutaneous tissue. Differentiate purulent vs nonpurulent cellulitis; drain abscesses and choose antibiotics considering MRSA risk. Address risk factors (tinea pedis, edema, venous stasis) to prevent recurrence.


Treatment Strategy & Disposition

Stabilize ABCs. Initiate guideline‑concordant first‑line therapy with precise dosing and continuous monitoring. Escalate to advanced/procedural interventions based on explicit failure criteria. Define ICU, step‑down, and ward disposition triggers; involve specialty teams early.


Epidemiology / Risk Factors

  • Risk varies by comorbidity and precipitants; see citations for condition‑specific data.

Investigations

TestRole / RationaleTypical FindingsNotes
Clinical exam and ultrasound (abscess?)PhenotypePurulent vs nonpurulentGuides therapy
Cultures (if purulent, severe, or immunocompromised)EtiologyMRSA/MSSA/streptococciTailor therapy
Assess predisposing conditions (edema, tinea)PreventionReduce recurrence

High-Risk & Disposition Triggers

TriggerWhy it mattersAction
Rapid progression/systemic toxicitySevere infectionAdmit; broad IV antibiotics; r/o NSTI
Facial/periorbital involvementComplicationsSpecialty consults

Pharmacology

Medication/InterventionMechanismOnsetRole in TherapyLimitations
Incision and drainage (purulent)Source controlImmediatePrimary therapy for abscess
Cephalexin/Dicloxacillin (nonpurulent) or TMP‑SMX/Doxycycline/Clindamycin (purulent/MRSA risk)AntibioticsHoursEmpiric coverageAdjust to culture
Elevation/compression and skin careAdjunctDaysReduce edema and recurrence

Prognosis / Complications

  • Outcome depends on timeliness of diagnosis and definitive therapy; monitor for complications.

Patient Education / Counseling

  • Provide red‑flag education, adherence guidance, and explicit return precautions; arrange timely specialty follow‑up.

References

  1. IDSA SSTI guideline — Link

Meet MDSteps: Smarter USMLE® Prep

MDSteps streamlines your study with an adaptive QBank (19,000+ high-yield MCQs across all 3 Steps), full CCS case simulations for Step 3 with live vitals and timed orders, and an exam-readiness dashboard that turns practice into insight. Build mastery by system and discipline, auto-create missed-item decks (Anki-exportable), and keep momentum with pacing guidance, trend lines, and suggested next sessions—so every block moves you closer to test-day confidence.

Compared with staples like UWorld and AMBOSS, MDSteps aims to give you the best of both worlds: exam-style practice that adapts to you, plus real-time analytics and a full CCS runner—all in one place. If you want targeted, exam-relevant reps with feedback that actually changes how you study, MDSteps is built for you.

Eplore MDSteps

You’ve reached your free library limit

You’ve viewed 5 of 5 free MDSteps Library topics.

Unlock full access to the MDSteps USMLE® Library, adaptive QBank, CCS simulator, and readiness analytics with a free trial.

  • Full access to all reference topics
  • 9,000+ NBME-style questions with teaching-grade rationales
  • Realistic CCS cases with live vitals
  • Exam readiness dashboard & study insights