II. Definitions
- Paronychia
- Superficial infection of distal phalanx along nail edge (nail fold)
- Affects perionychium (Epidermis at nail border)
- Acute Paronychia
- Typically infection-mediated Paronychia of a single digit lasting <6 weeks
-
Chronic Paronychia
- Typically irritant-mediated Paronychia of multiple digits lasting >6 weeks
III. Epidemiology
- More common in women (by 3 fold)
IV. Pathophysiology
- Disrupted seal between nail fold and nail plate
- Mechanisms of Acute Paronychia
- Local Penetrating Trauma
- Nail biting
- Finger sucking
- Aggressive manicure
- Ingrown Nails
- Hang nail (esp. if manipulated)
- Artificial nail placement (sculptured nails)
- Dermatitis (e.g. Pemphigus Vulgaris, Psoriasis, Eczematous Dermatitis, Irritant Contact Dermatitis)
- Occupational Trauma (e.g. bartenders, dish washers)
V. Etiology: Polymicrobial in many cases
-
Trauma related (most common)
- Staphylococcus aureus (common)
- Oral flora related from nail biting or sucking
- Streptococcus Pyogenes (common)
- Pseudomonas pyocyanea
- Gram Negative Bacteria (e.g. Proteus vulgaris)
- Other causes (oral Anaerobes, esp. Diabetes Mellitus, injection drug use)
- Bacteroides
- Fusobacterium nucleatum
VI. Symptoms
- Onset 2-5 days after Trauma
- Local pain at perionychium (Eponychium)
VII. Signs
- Distribution
- Single digit involvement (esp. fingers) is typical for Acute Paronychia
- Early: Perionychial inflammation
- Local redness
- Swelling
- Tenderness at nail edge to palpation
- Discolored nail
- Late: Complicated infection
- Abscess at perionychium (appears pale, white at distended paronychium)
- Nail bed infection
- May elevate nail plate
VIII. Signs: Digital Pressure Test
- Indication
- Diagnostic for early Paronychia with abscess before abscess is clearly demarcated
- Technique
- Patient opposes thumb and affected finger (applying pressure to pulp on volar aspect at finger tip)
- Positive test
- Abscess becomes demarcated with blanching
- Reference
IX. Precautions
- Acute Paronychia typically involves only a single digit (unlike Chronic Paronychia which involves multiple)
- Consider systemic conditions when Acute Paronychia involves multiple digits
X. Differential Diagnosis
- See Hand Infection
- Chronic Paronychia
- Felon (finger pad or pulp infection)
- Eczematous Dermatitis
- Herpetic Whitlow
- Cellulitis
- Tuft Fracture
- Psoriasis
- Dermatomyositis
- Granuloma Annulare
- Pyogenic Granuloma
- Reiter Syndrome
- Contact Dermatitis
- Maceration from excessive moisture
- Ingrown Toenail
- Melanoma
- Squamous Cell Skin Cancer
- Pemphigus Vulgaris
XI. Labs
- Avoid wound cultures (poor yield)
XII. Imaging
- Bedside Soft-Tissue Ultrasound
- May define abscess or deep space infection
XIII. Management: Incision and Drainage
- Anesthesia
- Contraindications
- Technique 1
- Often performed without Digital Block (blanched Paronychia roof is often without Sensation)
- Identify blanched skin over abscess (may use digital pressure test as above)
- Puncture abscess with #18 gauge needle in multiple sites to allow drainage
- Sliding the needle tip horizontally at the puncture site can enlarge the puncture and allow greater drainage
- Technique 2
- Digital BlockAnesthesia is required
- Pass #15 or #11 scalpel blade passed between nail and nail fold
- Abscess area should be clearly demarcated by overlying blanching of skin
- Direct blade away from nail
- Avoid entering through the Eponychium
- Avoid injury to cuticle
- May need to remove part of nail (or perform Nail Trephination) to expose subungual infection
- Indicated for subungual abscess
- Irrigate wound
- Larger wounds could be packed with small plain gauze
- Other measures
- Wound culture not indicated (poor yield)
- Post-procedure care
- Warm water soaks (or Burrows Soluition or acetic acid 1:1 dilution) 2-3 times daily for 3 days
- Topical and oral Antibiotics are not typically needed after Incision and Drainage
- Exceptions include significant Cellulitis, Immunocompromised state
XIV. Management: General Measures
- Soak 3-4 times daily for 15 minutes each
- Warm water or
- Burow's Solution (aluminum acetate) or
- Acetic acid soaks (1:1 vinegar in water)
- Splint affected finger
- Tetanus Prophylaxis
-
Incision and Drainage
- Indicated if abscess pocket is delineated (see below)
-
Antibiotics: Topical in early, mild cases
- Bactroban twice daily for 5-10 days or
- Gentamicin ointment three times daily for 5-10 days
- Topical Fluoroquinolone
- Indicated for suspected Pseudomonas infection (green discoloration, moist environment)
- Neomycin ointment
- Has been used in the past for pseudomonal Paronychia
- Higher risk of Allergic Reaction (10%) and generally avoided
- Consider with adjunctive Topical Corticosteroid (medium to high potency)
- Speeds healing time
- Wollina (2001) J Eur Acad Dermatol Venereol 15:82-4 [PubMed]
-
Antibiotics: Systemic in persistent, moderate to severe cases with associated Cellulitis
- Antibiotics are not typically needed after Incision and Drainage
- Limit to Immunocompromised patients or with severe infections and ill appearing patients
- History may direct specific Antibiotics
- Traumatic cause in region where MRSA is common
- Nail biting cause directs Antibiotic coverage for oral flora
- Green discoloration (esp repeat Trauma in chronically moist environments) may direct Pseudomonas coverage
- First line (for Staphylococcus aureus if Trauma is source as opposed to oral flora)
- Second Line: MRSA suspected
- Second Line (for Gram Negatives and Anaerobes if oral flora source suspected)
- Clindamycin
- Amoxicillin-Clavulanate (Augmentin)
- Trimethoprim Sulfamethoxazole (Septra)
- Fluoroquinolones (e.g. Ciprofloxacin)
- Pseudomonas coverage (green discharge)
- Antibiotics are not typically needed after Incision and Drainage
XV. 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
- Consider Rubber gloves (and cotton liners) when working in moist environments (e.g. dish washing)
XVI. Complications
- Chronic Paronychia (from recurrent Acute Paronychia)
XVII. References
- Warrington (2023) Crit Dec Emerg Med 37(6): 23
- Brook (1990) Ann Emerg Med 19:994-6 [PubMed]
- Hochman (1995) Int J Dermatol 34:385-6 [PubMed]
- Jebson (1998) Hand Clin 14:547-55 [PubMed]
- Leggit (2017) Am Fam Physician 96(1): 44-51 [PubMed]
- Rerucha (2019) Am Fam Physician 99(4):228-36 [PubMed]
- Rigopoulos (2008) Am Fam Physician 77:339-48 [PubMed]
- Rockwell (2001) Am Fam Physician 63(6): 113-6 [PubMed]