Treatment of Finger Cellulitis
For typical non-purulent finger cellulitis, start with oral cephalexin 500 mg four times daily or dicloxacillin 250-500 mg every 6 hours for exactly 5 days, extending only if symptoms have not improved by day 5. 1
First-Line Antibiotic Selection
The causative organisms in finger cellulitis are predominantly β-hemolytic streptococci and methicillin-sensitive Staphylococcus aureus, making beta-lactam monotherapy the standard of care with a 96% success rate. 2, 1
Recommended oral regimens include:
- Cephalexin 500 mg four times daily 1
- Dicloxacillin 125-250 mg every 6 hours for mild to moderate infections, or 250 mg every 6 hours for severe infections 3
- Amoxicillin (appropriate dosing for streptococcal coverage) 1
- Penicillin 1
For penicillin-allergic patients, clindamycin 300-450 mg every 6 hours provides excellent coverage for both streptococci and MRSA without requiring combination therapy. 1, 4
Treatment Duration
Treat for exactly 5 days if clinical improvement occurs. This duration is as effective as 10-day courses for uncomplicated cellulitis. 1 Extend treatment only if the infection has not improved within the initial 5-day period. 1
When MRSA Coverage Is NOT Needed
MRSA is an unusual cause of typical finger cellulitis, and empiric MRSA coverage is unnecessary in most cases. 1 Do not reflexively add MRSA-active antibiotics for standard non-purulent finger cellulitis. 1
When to Add MRSA Coverage
Add MRSA-active therapy only when specific risk factors are present: 1
- Penetrating trauma to the finger 1
- Purulent drainage 1
- History of injection drug use 1
- Evidence of MRSA infection elsewhere 1
- Systemic inflammatory response syndrome (SIRS) 1
If MRSA coverage is needed, use clindamycin 300-450 mg every 6 hours as monotherapy (covers both streptococci and MRSA). 1, 4
Critical Adjunctive Measures
Elevate the affected finger above heart level to promote gravity drainage of edema and inflammatory substances—this simple measure hastens resolution and is often neglected. 1
For non-diabetic adults, consider prednisone 40 mg daily for 7 days to reduce inflammation and accelerate healing, though evidence is limited. 1
Hospitalization Criteria
Most finger cellulitis can be managed outpatient. 1 Hospitalize only if: 1
- Systemic inflammatory response syndrome (SIRS) present 1
- Altered mental status or hemodynamic instability 1
- Concern for deeper or necrotizing infection 1
- Severe immunocompromise 1
- Poor adherence to outpatient therapy 1
Common Pitfalls to Avoid
Do not extend treatment beyond 5 days if clinical improvement has occurred—this represents unnecessary antibiotic exposure without added benefit. 1
Do not automatically add MRSA coverage for typical non-purulent finger cellulitis without specific risk factors, as this contributes to antibiotic resistance and increased adverse effects. 1
Do not obtain blood cultures or tissue aspirates for typical cases—these are not routinely needed and have poor yield. 1
Administration Details
Dicloxacillin should be taken on an empty stomach, at least 1 hour before or 2 hours after meals, with at least 4 fluid ounces (120 mL) of water, and not in the supine position or immediately before bed. 3
Clindamycin capsules should be taken with a full glass of water to avoid esophageal irritation. 4
Prevention of Recurrence
Identify and treat predisposing conditions such as chronic skin trauma, occupational exposures, or underlying skin disorders. 1 For patients with 3-4 episodes per year despite addressing risk factors, consider prophylactic antibiotics such as oral penicillin, erythromycin, or intramuscular benzathine penicillin. 1