In a stable pediatric patient with fever, irritability, and a progressively enlarging erythematous swelling of the lower left leg without systemic toxicity, what is the most appropriate management?

Management of Progressive Spreading Cellulitis in a Stable Pediatric Patient

In a hemodynamically stable pediatric patient with fever, irritability, and progressively spreading cellulitis of the lower leg, the most appropriate management is oral flucloxacillin with close follow-up within 24-48 hours (Answer B). 1

Rationale for Oral Antibiotic Management

Oral antibiotics are as effective as IV therapy for uncomplicated cellulitis in stable children. 1 The key clinical features supporting outpatient oral management in this case include:

• Stable vital signs – no hypotension, severe tachycardia, or respiratory distress 1
• No systemic toxicity – despite fever and irritability, the child lacks signs of sepsis or shock 1
• Localized infection – the spreading erythema represents uncomplicated cellulitis without evidence of deeper infection (no necrotizing fasciitis, abscess, or osteomyelitis) 1

Recommended Treatment Protocol

Initial Management

• Start oral cephalexin (or flucloxacillin) at standard pediatric dosing to cover common causative organisms (Staphylococcus aureus and Streptococcus pyogenes) 1
• Mark the borders of erythema with a pen to objectively monitor progression versus improvement 1
• Schedule mandatory follow-up within 24-48 hours to assess clinical response 1

Follow-Up Assessment

At the 24-48 hour follow-up, evaluate for:

• Reduction in erythema, warmth, and swelling
• Resolution of fever
• Improvement in irritability and overall appearance
• Absence of new concerning features (see escalation criteria below)

When to Escalate to IV Antibiotics

IV antibiotics with surgical consultation (Answer C) would be indicated if the child develops any of the following: 1

• Clinical instability – hypotension, severe tachycardia, altered mental status 1
• Signs of deeper infection – crepitus, bullae, skin necrosis, disproportionate pain, rapid progression despite oral antibiotics 1
• Systemic toxicity – persistent high fever, rigors, signs of sepsis 1
• Failure to improve – worsening erythema or no improvement after 48-72 hours of oral therapy 1

Why Other Options Are Incorrect

Option A (Oral flucloxacillin with topical antibiotics)

Topical antibiotics have no role in the treatment of cellulitis, which is a deeper soft tissue infection requiring systemic therapy. 1

Option C (IV antibiotics with surgical consultation)

This represents overtreatment for a stable child with uncomplicated cellulitis. Reserve IV therapy and surgical consultation for clinically unstable patients or those with signs of deeper infection. 1 Starting with IV antibiotics in a stable patient unnecessarily increases healthcare costs, requires hospitalization or OPAT infrastructure, and exposes the child to IV line complications without proven benefit over oral therapy. 1

Option D (MRI)

MRI is not indicated as initial management for straightforward cellulitis. Imaging should be reserved for cases where deeper infection (abscess, necrotizing fasciitis, osteomyelitis) is suspected based on clinical features such as crepitus, severe pain out of proportion to examination, failure to respond to appropriate antibiotics, or concern for underlying bone involvement. 1

Critical Pitfalls to Avoid

• Do not hospitalize stable children with uncomplicated cellulitis – oral outpatient management is equally effective and improves quality of life while reducing costs 1
• Do not skip the mandatory 24-48 hour follow-up – cellulitis can progress rapidly, and early reassessment ensures timely escalation if needed 1
• Do not add topical antibiotics – they provide no additional benefit and may cause contact dermatitis 1
• Do not order MRI routinely – clinical assessment guides the need for imaging, not the presence of spreading erythema alone 1

Special Considerations in the Current Context

While the provided evidence includes extensive discussion of MIS-C and febrile neutropenia, these conditions are not relevant to this clinical scenario. 2 The patient presents with classic localized cellulitis without:

• Multi-organ involvement (MIS-C requires cardiac, GI, or other systemic features) 2
• Neutropenia (no mention of cancer, chemotherapy, or immunosuppression) 2
• COVID-19 exposure or systemic inflammatory features 2

The straightforward presentation of progressive localized erythema with stable vitals in an otherwise healthy child points to uncomplicated cellulitis requiring oral antibiotics and close follow-up. 1