Paronychia: Etiology, Surgical Anatomy, and Management for Orthopedic Specialists
Key Takeaway
Paronychia is the most common hand infection, inflaming nail folds. It's acute (bacterial) or chronic (fungal/multifactorial). Orthopedic specialists require deep knowledge of its epidemiology, forms, and surgical anatomy for precise diagnosis, effective management, and to prevent severe complications like osteomyelitis.
A 28-year-old barista presents with a 4-day history of increasing pain, swelling, and redness at the radial aspect of her index finger nail fold. She has tried warm water soaks at home with minimal relief. On examination, there is localized erythema and a small, fluctuant collection at the radial nail fold. There is no spread beyond the paronychium, and neurovascular status is intact.
How would you manage this patient, and what is your specific surgical approach if you decide to proceed?
Candidate: I would diagnose an acute lateral paronychia with abscess formation. Given the presence of a fluctuant collection, I would perform an incision and drainage under a digital block. I would make a longitudinal incision along the lateral nail fold, irrigate, and place a small wick. I would also counsel her on keeping the hand dry given her occupation.
Failing to mention the exclusion of Herpetic Whitlow, which is the most critical differential diagnosis. Also, blindly cutting without discussing the need to preserve the nail matrix or failing to mention culture and sensitivity, which is vital for a patient likely exposed to diverse organisms in her occupation.
Structure your answer: 1. Assessment: Confirm diagnosis of acute paronychia with abscess. Rule out Herpetic Whitlow (look for vesicles, systemic symptoms). 2. Decision: Surgical drainage is indicated due to fluctuance. 3. Technique: Digital block (1% lidocaine w/o epinephrine), tourniquet for bloodless field. Use a #11 blade to lift the nail fold parallel to the plate or a short longitudinal incision. Crucially, avoid the nail matrix and do not perform transverse incisions to prevent nail deformity. 4. Adjuncts: Obtain pus for culture/sensitivity. Pack with a wick for 24-48 hours. 5. Post-op: Tetanus update, oral antibiotics (e.g., cephalexin targeting S. aureus), and education on preventing moisture/trauma (e.g., gloves for her job).
The patient returns 48 hours later. The infection has progressed; the redness now tracks proximally under the eponychium and involves the ulnar lateral nail fold as well. She is now complaining of significant pain. What do you suspect, and how does this change your management?
Candidate: This suggests a 'horseshoe abscess' where the infection has tracked beneath the eponychium. I need to perform a more formal drainage. I will perform lateral incisions on both sides and lift the eponychial fold off the nail plate to ensure the proximal space is drained.
Candidates often suggest an "H-incision" or "Omega incision." Examiners will penalize this heavily because crossing the eponychial fold transversely often leads to permanent nail matrix scarring and deformity. Acknowledge this, then explicitly reject it.
Identify this as a horseshoe abscess. Management: Surgical debridement is mandatory. Technique: Perform longitudinal incisions on both the radial and ulnar lateral nail folds. Using a Freer elevator, gently elevate the eponychium off the nail plate to drain the proximal pocket. Do NOT cross the eponychium transversely. If there is a subungual abscess, consider partial or full nail plate avulsion to allow adequate drainage and direct visualization of the sterile matrix. Document your plan to preserve the germinal matrix to avoid permanent onychodystrophy.
