What is the treatment for paronychia and felon with green pus and significant swelling?

Management of Paronychia and Felon with Green Pus and Significant Swelling

This patient requires immediate surgical incision and drainage followed by oral antibiotics covering Pseudomonas aeruginosa (indicated by green pus), with no role for topical therapy alone given the severity of infection. 1, 2

Immediate Surgical Management

Surgical drainage is the most critical intervention and must be performed urgently. 3, 4

• The presence of quarter-size swelling with expressed pus indicates an established abscess requiring complete surgical excision 5
• Stiffness with finger bending suggests deep tissue involvement or potential flexor tenosynovitis, which is a surgical emergency 4, 6
• Adequate drainage is more important than antibiotic therapy—antibiotics should never replace proper incision and drainage 7, 5

Critical Pitfall to Avoid

• Inadequate surgical excision is the primary cause of treatment failure, not lack of antibiotics 5
• The single most important factor for successful outcome is completeness of the surgical drainage 5

Antibiotic Selection

The green color of the pus strongly suggests Pseudomonas aeruginosa infection, which requires specific antibiotic coverage.

• Start oral fluoroquinolone (ciprofloxacin or levofloxacin) immediately to cover Pseudomonas 2
• If Pseudomonas is not confirmed and MRSA is suspected, switch to sulfamethoxazole-trimethoprim (Bactrim) which provides broader coverage than cephalexin 2
• Obtain bacterial culture from the purulent drainage to guide definitive antibiotic therapy 2
• Secondary bacterial or fungal superinfections occur in up to 25% of paronychia cases 1, 2

Important Consideration

• Cephalexin and other first-generation cephalosporins do NOT cover Pseudomonas and would be inappropriate given the green pus 2

Adjunctive Local Care

After surgical drainage, implement the following:

• Apply topical 2% povidone-iodine twice daily to the surgical site 1, 2
• Perform antiseptic soaks with dilute vinegar (50:50 dilution) or povidone-iodine for 10-15 minutes twice daily 1
• Elevate the hand above heart level continuously for the first 48-72 hours 4, 7
• Splint the finger to prevent motion and reduce pain 4

Assessment for Complications

Given the stiffness with finger bending, you must rule out deeper infections:

• Evaluate for pyogenic flexor tenosynovitis using Kanavel's signs (this requires parenteral antibiotics and surgical irrigation if present) 4
• Check for septic arthritis or osteomyelitis, which would require more aggressive surgical debridement 6
• Assess for deep space infection extending beyond the nail fold 6

Follow-up Protocol

• Reassess within 48 hours after drainage to ensure improvement 1, 2
• If no improvement after 2 weeks of appropriate treatment, refer to hand surgery (for finger) or podiatry (for toe) 1, 8
• Complete healing typically occurs within 2-3 weeks with proper drainage 5

When Antibiotics Are NOT Needed

• In uncomplicated cases after complete surgical excision in immunocompetent patients, antibiotics may not be necessary 5
• However, this patient's significant swelling, stiffness, and green pus indicate a complicated infection requiring antibiotic coverage 2, 5

Special Populations Requiring Enhanced Treatment

• Diabetic patients require more aggressive treatment including possible IV antibiotics 9, 7
• Immunosuppressed patients should receive systemic antibiotics regardless of infection severity 7, 5

Prevention of Recurrence

• Trim nails straight across, not too short 1
• Avoid trauma to the nail fold and cuticles 1
• Wear protective gloves during water exposure or chemical handling 1, 2
• Apply regular emollients to periungual tissues 1, 2