Clinical Assessment: Mrs Vijayabai Prakash Somawanshi, 60F

Most Likely Diagnosis: FELON (Pulp Space Abscess)

• Current Surgical Therapy 14e, p. 975
• Bailey and Love's Short Practice of Surgery 28th Ed, Ch. 38

Anatomy - Why Felons Are Painful and Dangerous

• Intense throbbing pain (the hallmark)
• Risk of ischemia and tissue necrosis
• Potential spread to the periosteum → osteomyelitis of the distal phalanx
• Proximal spread through the fibrous curtain into the flexor sheath → flexor tenosynovitis
• Extension to the DIP joint → septic arthritis

Clinical Features - This Patient's Presentation Fits Perfectly

Differential Diagnoses to Consider

Investigation

• Clinical diagnosis - largely based on history and examination
• X-ray of the thumb: rule out foreign body, assess for osteomyelitis (may be normal early)
• Blood tests: CBC (leukocytosis), CRP, ESR, blood glucose (screen for diabetes)
• Wound culture and sensitivity from drainage (intraoperatively)
• Gram stain and culture if chronic or atypical

Management

Stage 1 - Early (No fluctuance yet)

• Rest, elevation of the hand
• Warm saline/soapy soaks
• Oral anti-staphylococcal antibiotics (first-generation cephalosporin - e.g., cefalexin; or clindamycin if penicillin-allergic)
• If MRSA suspected (healthcare worker, prior MRSA, diabetic): trimethoprim-sulfamethoxazole (TMP-SMX) orally; vancomycin IV if inpatient

Stage 2 - Established Abscess (Fluctuance present - likely in this patient at 3 days with fever)

1. Digital block anesthesia + finger tourniquet
2. For the thumb (digit 1): incision placed on the radial side (Incisions for digits 2-4 are placed on the ulnar side)
3. A unilateral longitudinal incision is preferred (incision E in diagram below) - placed on the side of maximal tenderness, avoiding the pinching surface
4. Midline vertical incision if the abscess points volarly toward the fingerprint whorl (incision D)
5. Gently open compartments with a small mosquito clamp - do not violate all septa aggressively
6. Thorough drainage and irrigation; send cultures
7. Pack the wound; dressing changes 2-3x/day with warm soapy soaks

Post-operative

• Oral antibiotics: first-generation cephalosporin or clindamycin
• If severe/systemic: IV antibiotics - Bailey & Love recommends IV antibiotics following I&D
• Elevation and splinting
• Wound check at 48 hours
• Early mobilization once infection resolves

Red Flags - Admit / Refer to Hand Surgery If:

• Signs of flexor tenosynovitis (Kanavel's signs)
• Spreading cellulitis up the forearm
• Systemic sepsis (high fever, rigors, tachycardia)
• Suspected osteomyelitis on X-ray
• Immunocompromised or poorly controlled diabetes
• Failure to improve after 48 hours of I&D + antibiotics
• The thumb's flexor sheath communicates with the radial bursa, which can spread infection toward the wrist - making thumb felons higher-risk than finger felons

Summary Box (Bailey & Love 28th Ed)

• Elevate and splint in a functional position + IV antibiotics
• Surgical drainage (I&D) - tendon sheath irrigation if tenosynovitis
• Early mobilization

Given this patient is a 60-year-old woman with fever at 3 days post-prick, she almost certainly has an established abscess and should proceed to I&D under digital block, with cultures, packing, and oral anti-staphylococcal antibiotics. Screen for diabetes. If systemic signs are prominent or she is diabetic, admit for IV antibiotics and hand surgery review.

🏥 Prescription

Rx

Local / Procedural

Adjunct / Supportive

Investigations

• CBC, RBS (rule out diabetes - important at 60F)
• X-ray L thumb AP/Lateral (rule out foreign body, osteomyelitis)
• Pus C&S (intraoperative)

Follow-up

⚠ Return Immediately If:

• Fever worsens or new chills/rigors
• Swelling spreads to the hand or forearm
• Finger becomes numb or discolored (blue/white)
• No improvement after 48 hours

Note: If blood glucose is elevated or patient is found to be diabetic, upgrade to IV antibiotics (Inj. Amoxicillin-Clavulanate or Piperacillin-Tazobactam) and refer to hand surgery. Adjust antibiotic choice based on C&S report when available.

1. Why Metronidazole?

Why I included it (reasoning):

• Metronidazole covers anaerobic organisms
• In penetrating wounds (prick injuries), especially in soil/dirty environments, anaerobic cover is sometimes added empirically

Why it's actually NOT needed here:

• A felon is overwhelmingly caused by Staphylococcus aureus - an aerobe
• Amoxicillin-Clavulanate (625 mg) already provides adequate anaerobic cover on its own (clavulanate broadens spectrum to include anaerobes and beta-lactamase producers)
• Adding metronidazole on top is redundant and unnecessary in a straightforward felon
• It adds side effects (nausea, metallic taste, drug interactions) without benefit

Verdict: Remove metronidazole from the prescription. It was overcautious and not evidence-based for this indication.

2. Why Not Zerodol-SP?

It is actually a reasonable choice here. Here's a balanced view:

Why I chose Diclofenac+Paracetamol instead:

• Diclofenac 50 mg is a slightly stronger analgesic than Aceclofenac 100 mg for acute pain
• The fever in this patient makes a dedicated antipyretic dose (Paracetamol 500-650 mg) preferable over the 325 mg in Zerodol-SP
• Serratiopeptidase evidence is weak (not consistently supported by RCTs)

Why Zerodol-SP is still acceptable:

• Very commonly used in Indian surgical practice
• The anti-edema effect of serratiopeptidase, though debated, is clinically perceived as helpful post-I&D
• Well-tolerated combination
• Convenient single tablet

Verdict: Zerodol-SP can be used. It is a practical, widely-used choice in this setting. Just be aware the paracetamol dose is low (325 mg) - if fever is significant, you may want to add a separate Tab. Paracetamol 500 mg SOS for temperature spikes.

Corrected Prescription (Revised)