Acute Paronychia

See Also

Definitions

Paronychia
1. Superficial infection of distal phalanx along nail edge (nail fold)
2. Affects perionychium (Epidermis at nail border)
Acute Paronychia
1. Typically infection-mediated Paronychia of a single digit lasting <6 weeks
Chronic Paronychia
1. Typically irritant-mediated Paronychia of multiple digits lasting >6 weeks

Epidemiology

More common in women (by 3 fold)

Pathophysiology

Disrupted seal between nail fold and nail plate
Mechanisms of Acute Paronychia
1. Local Penetrating Trauma
2. Nail biting
3. Finger sucking
4. Aggressive manicure
5. Ingrown Nails
6. Hang nail (esp. if manipulated)
7. Artificial nail placement (sculptured nails)
8. Dermatitis (e.g. Pemphigus Vulgaris, Psoriasis, Eczematous Dermatitis, Irritant Contact Dermatitis)
9. Occupational Trauma (e.g. bartenders, dish washers)

Etiology
Polymicrobial in many cases

Trauma related (most common)
1. Staphylococcus aureus (common)
Oral flora related from nail biting or sucking
1. Streptococcus Pyogenes (common)
2. Pseudomonas pyocyanea
3. Gram Negative Bacteria (e.g. Proteus vulgaris)
Other causes (oral Anaerobes, esp. Diabetes Mellitus, injection drug use)
1. Bacteroides
2. Fusobacterium nucleatum

Symptoms

Onset 2-5 days after Trauma
Local pain at perionychium (Eponychium)

Signs

Distribution
1. Single digit involvement (esp. fingers) is typical for Acute Paronychia
Early: Perionychial inflammation
1. Local redness
2. Swelling
3. Tenderness at nail edge to palpation
4. Discolored nail
Late: Complicated infection
1. Abscess at perionychium (appears pale, white at distended paronychium)
2. Nail bed infection
3. May elevate nail plate

Signs
Digital Pressure Test

Indication
1. Diagnostic for early Paronychia with abscess before abscess is clearly demarcated
Technique
1. Patient opposes thumb and affected finger (applying pressure to pulp on volar aspect at finger tip)
Positive test
1. Abscess becomes demarcated with blanching
Reference
1. Turkmen (2004) Br J Plast Surg 57:93-4 [PubMed]

Precautions

Acute Paronychia typically involves only a single digit (unlike Chronic Paronychia which involves multiple)
1. Consider systemic conditions when Acute Paronychia involves multiple digits

Differential Diagnosis

Labs

Avoid wound cultures (poor yield)

Imaging

Bedside Soft-Tissue Ultrasound
1. May define abscess or deep space infection

Management
Incision and Drainage

Anesthesia
1. Digital Block (Metacarpal Block) or
2. Wing Block
Contraindications
1. Herpetic Whitlow
Technique 1
1. Often performed without Digital Block (blanched Paronychia roof is often without Sensation)
2. Identify blanched skin over abscess (may use digital pressure test as above)
3. Puncture abscess with #18 gauge needle in multiple sites to allow drainage
  1. Sliding the needle tip horizontally at the puncture site can enlarge the puncture and allow greater drainage
Technique 2
1. Digital Block Anesthesia is required
2. Pass #15 or #11 scalpel blade passed between nail and nail fold
  1. Abscess area should be clearly demarcated by overlying blanching of skin
  2. Direct blade away from nail
  3. Avoid entering through the Eponychium
  4. Avoid injury to cuticle
3. May need to remove part of nail (or perform Nail Trephination) to expose subungual infection
  1. Indicated for subungual abscess
4. Irrigate wound
5. Larger wounds could be packed with small plain gauze
Other measures
1. Wound culture not indicated (poor yield)
Post-procedure care
1. Warm water soaks (or Burrows Soluition or acetic acid 1:1 dilution) 2-3 times daily for 3 days
2. Topical and oral Antibiotics are not typically needed after Incision and Drainage
  1. Exceptions include significant Cellulitis, Immunocompromised state

Management
General Measures

Soak 3-4 times daily for 15 minutes each
1. Warm water or
2. Burow's Solution (aluminum acetate) or
3. Acetic acid soaks (1:1 vinegar in water)
Splint affected finger
Tetanus Prophylaxis
Incision and Drainage
1. Indicated if abscess pocket is delineated (see below)
Antibiotics: Topical in early, mild cases
1. Bactroban twice daily for 5-10 days or
2. Gentamicin ointment three times daily for 5-10 days
3. Topical Fluoroquinolone
  1. Indicated for suspected Pseudomonas infection (green discoloration, moist environment)
4. Neomycin ointment
  1. Has been used in the past for pseudomonal Paronychia
  2. Higher risk of Allergic Reaction (10%) and generally avoided
5. Consider with adjunctive Topical Corticosteroid (medium to high potency)
  1. Speeds healing time
  2. Wollina (2001) J Eur Acad Dermatol Venereol 15:82-4 [PubMed]
Antibiotics: Systemic in persistent, moderate to severe cases with associated Cellulitis
1. Antibiotics are not typically needed after Incision and Drainage
  1. Limit to Immunocompromised patients or with severe infections and ill appearing patients
2. History may direct specific Antibiotics
  1. Traumatic cause in region where MRSA is common
  2. Nail biting cause directs Antibiotic coverage for oral flora
  3. Green discoloration (esp repeat Trauma in chronically moist environments) may direct Pseudomonas coverage
3. First line (for Staphylococcus aureus if Trauma is source as opposed to oral flora)
  1. Cephalexin (Keflex)
  2. Dicloxacillin
4. Second Line: MRSA suspected
  1. Trimethoprim Sulfamethoxazole (Septra)
  2. Doxycycline
5. Second Line (for Gram Negatives and Anaerobes if oral flora source suspected)
  1. Clindamycin
  2. Amoxicillin-Clavulanate (Augmentin)
  3. Trimethoprim Sulfamethoxazole (Septra)
  4. Fluoroquinolones (e.g. Ciprofloxacin)
6. Pseudomonas coverage (green discharge)
  1. Ciprofloxacin

Prevention

Avoid nail Trauma from nail biting, picking or sucking
Do not trim or remove cuticles
Keep finger nails clean and dry, and keep nails short
Apply Moisturizing Lotion after Hand Washing
Optimize Glucose control in Diabetes Mellitus
Avoid recurrent prolonged exposure to moisture and causes of contact irritant dermatitis
1. Consider Rubber gloves (and cotton liners) when working in moist environments (e.g. dish washing)

Complications

Chronic Paronychia (from recurrent Acute Paronychia)

References