What is the best course of action for managing cellulitis at an ambulatory infusion site in a patient receiving intravenous (IV) medication?

Management of Cellulitis at Ambulatory Infusion Site

Remove the peripheral venous catheter immediately and initiate empiric antibiotic therapy targeting β-hemolytic Streptococcus and methicillin-sensitive Staphylococcus aureus with oral agents such as cephalexin or amoxicillin for 5 days. 1, 2, 3

Immediate Catheter Management

The catheter must be removed immediately when cellulitis is present at the infusion site. 1, 4

• The CDC guidelines explicitly state that catheters should be removed if there is erythema overlying the catheter insertion site or purulence at the insertion site 1
• Peripheral venous catheters should be replaced at least every 72-96 hours in adults to prevent phlebitis, but immediate removal is indicated when infection is suspected or documented 1, 4
• Do not attempt catheter salvage or guidewire exchange for peripheral catheters with cellulitis—these techniques are reserved only for central venous catheters when no alternative vascular access exists 1

Site Care and Infection Control

Clean the infected area with 0.5-2% alcoholic chlorhexidine solution and allow it to completely dry before applying sterile dressing. 4

• Perform hand antisepsis with alcohol-based hand rubs before and after handling the infected site to prevent transmission 4
• Apply gauze dressings if the site is bleeding or oozing 4
• Change dressings regularly and inspect the wound for signs of worsening infection 4
• Do not submerge the affected area in water, though showering may be permitted if the wound is properly protected 4

Antibiotic Selection

Initiate oral antibiotics targeting Streptococcus and methicillin-sensitive S. aureus as first-line therapy. 2, 3

Standard First-Line Coverage:

• β-hemolytic Streptococcus and methicillin-sensitive S. aureus cause the majority of identifiable cellulitis cases (approximately 15% of cases yield positive cultures) 2
• Appropriate oral agents include penicillin, amoxicillin, or cephalexin 3
• Five days of treatment is sufficient, with extension only if symptoms have not improved 2

MRSA Coverage Considerations:

• Do NOT routinely cover MRSA for non-purulent cellulitis at IV sites 3
• Add MRSA coverage only if specific risk factors are present: athletes, children, men who have sex with men, prisoners, military recruits, long-term care facility residents, prior MRSA exposure, or intravenous drug users 2
• Even with rising community-acquired MRSA rates, coverage for non-purulent cellulitis is generally not recommended 3

Clinical Monitoring

Reassess within 48-72 hours to ensure clinical improvement. 2, 5

• Failure to improve with appropriate first-line antibiotics should prompt consideration for resistant organisms, secondary conditions mimicking cellulitis, or underlying complicating conditions such as immunosuppression, chronic liver disease, or chronic kidney disease 2
• Look for reduction in erythema, warmth, tenderness, and swelling as markers of treatment response 5, 6
• If symptoms worsen or fail to improve, obtain blood cultures and consider imaging to rule out deeper infection or abscess formation 5

Common Pitfalls to Avoid

Do not administer prophylactic systemic antimicrobials routinely before catheter insertion or during use—this is explicitly contraindicated. 1

• Many conditions mimic cellulitis including venous stasis dermatitis, contact dermatitis, eczema, lymphedema, and erythema migrans 3
• Misdiagnosis leads to unnecessary hospitalizations and antibiotic overuse 6
• Microbiological diagnosis is often unobtainable due to poor sensitivity of culture specimens (only 15% of cases yield positive cultures) 2, 3
• Do not use filters routinely for infection-control purposes 1

Prevention of Recurrence

Address predisposing factors to minimize risk of future episodes. 2, 7

• Risk factors include prior episodes of cellulitis, cutaneous lesions, tinea pedis, and chronic edema 7
• Designate trained personnel for insertion and maintenance of intravascular catheters 1, 4
• Use aseptic non-touch technique when handling catheters and changing dressings 4
• Clean injection ports with 70% alcohol or iodophor before accessing the system 1, 4
• For patients with frequent recurrences despite management of underlying conditions, antimicrobial prophylaxis can be effective 7