What is the treatment for a quarter-sized abscess (collection of pus) on the side of my fingernail, causing stiffness in my finger?

Treatment of Quarter-Sized Abscess on Side of Fingernail with Finger Stiffness

This abscess requires immediate incision and drainage as the primary treatment, with antibiotics reserved only if there are signs of spreading cellulitis, systemic infection, or if you are immunocompromised. 1, 2

Immediate Management: Incision and Drainage

Surgical drainage is mandatory and should be performed promptly to prevent progression to deeper structures and restore finger mobility. 1, 2, 3

• The abscess should be drained through adequate incision under local digital anesthesia, with extensive lavage of the cavity 4
• Make a surgically appropriate incision that allows complete drainage without injuring adjacent structures 5
• Obtain bacterial culture from the purulent material to guide any subsequent antibiotic therapy if needed 2, 4
• The finger stiffness you're experiencing suggests the infection may be affecting the flexor tendon sheath or causing significant soft tissue inflammation, making prompt drainage even more critical 3

When Antibiotics Are NOT Needed

For a simple abscess without surrounding cellulitis, antibiotics are unnecessary after adequate drainage. 1

• If the erythema and induration are confined only to the defined area of the abscess and don't extend beyond its borders, drainage alone is sufficient 1
• A study of 103 acute fingertip infections showed no recurrences when treated with excision and drainage alone, without routine antibiotics 4
• Antibiotics do not improve healing in simple abscesses that are adequately drained 6

When Antibiotics ARE Indicated

Add antibiotic therapy if any of the following are present: 1, 2

• Significant cellulitis extending beyond the abscess borders
• Systemic signs of infection (fever, elevated white blood cell count)
• Immunocompromised status
• Incomplete source control after drainage
• Signs of deeper infection such as flexor tenosynovitis (severe pain with passive finger extension, fusiform finger swelling, finger held in flexion) 3

Antibiotic Selection

• First-line: Cephalexin is recommended as the most effective choice for bacterial nailbed infections, particularly against Staphylococcus aureus and Streptococcus pyogenes 2
• If MRSA is suspected: Use glycopeptides (vancomycin) or newer anti-MRSA agents, particularly in areas where community-acquired MRSA is prevalent 1
• The most common organisms in fingertip abscesses are Staphylococcus aureus (58.3%), polymicrobial flora (16.5%), and Streptococcus (12.6%) 4

Post-Drainage Care

• Keep the affected area clean and dry between warm water or saline soaks 2, 3
• Elevate the hand to reduce swelling 3
• Splint the finger if significant inflammation persists 3
• Packing may be considered if the abscess cavity is larger than 5 cm to reduce recurrence 6
• Avoid manipulation of cuticles and nail biting 2

Follow-Up and Red Flags

• Reassess at first dressing change (5-7 days) to monitor healing 4
• If infection worsens or doesn't improve after 2 weeks, consider alternative antibiotics based on culture results or further surgical intervention 2
• The finger stiffness should improve after drainage; persistent stiffness may indicate deeper infection requiring specialty consultation 3, 4

Critical Pitfall to Avoid

Do not start antibiotics without drainage - an undrained abscess will not respond to antibiotics alone and can progress to involve deeper structures including tendons, joints, and bone. 1, 3 The quarter-sized nature of your abscess makes drainage absolutely essential before any other treatment consideration.