DESCRIPTION

• Disruption of the seal between the nail plate and the nail fold may allow entry of bacteria into the eponychial space.
• Inflammation of the nail folds surrounding the nail plate

ETIOLOGY

• Acute paronychia: Predominantly Staphylococcus aureus but also streptococci, Pseudomonas, and anaerobes
• Chronic paronychia: Multifactorial due to allergens and irritants in addition to fungal etiologies, predominantly Candida albicans, which commonly coexist with Staphylococcus species

[Outline]

• DESCRIPTION
• ETIOLOGY

SIGNS AND SYMPTOMS

• Pain, warmth, and swelling to the proximal and lateral nail folds, often 2–5 days after trauma
• Symptoms must be present for 6 wk to meet criteria for a chronic paronychia.

History

• Acute paronychia: Nail biting, finger sucking, aggressive manicuring or manipulation, and trauma predispose to development.
• Chronic paronychia: Occupations with persistent moist hands; dish washers, bartenders; also increased in patients with peripheral vascular disease or diabetes

Pediatric Considerations

Frequently anaerobic mouth flora in children from nail biting

Physical Exam

• Begins as swelling, pain, and erythema in the dorsolateral corner of the nail fold bulging out over the nail plate
• Progresses to subcuticular/subungual abscess
• Green nail coloration suggests Pseudomonas
• Nail plate hypertrophy suggests fungal source

ESSENTIAL WORKUP

• History and physical exam with special attention to evaluating for concomitant infections such as felon or cellulitis
• Assess tetanus status.

DIAGNOSIS TESTS & INTERPRETATION

Lab

• No specific tests are useful.
• Cultures are not routinely indicated.
• Tzanck smear or viral culture if herpetic whitlow suspected.

Imaging

Soft tissue radiographs if foreign body is suspected; routine films if osteomyelitis suspected

Diagnostic Procedures/Surgery

Digital pressure test (opposing the thumb and the affected finger) may help identify the margins of an early subungual abscess

DIFFERENTIAL DIAGNOSIS

• Felon
• Herpetic whitlow
• Trauma or foreign body
• Primary squamous cell carcinoma
• Metastatic carcinoma
• Osteomyelitis
• Psoriasis
• Reiter syndrome
• Pyoderma gangrenosum
• Onychomycosis

[Outline]

• SIGNS AND SYMPTOMS
• ESSENTIAL WORKUP
• DIAGNOSIS TESTS & INTERPRETATION
• DIFFERENTIAL DIAGNOSIS

ED TREATMENT/PROCEDURES

Acute Paronychia

• Early paronychia without purulence may be managed with warm-water soaks 4 times a day with or without oral antibiotics; may also consider topical antibiotics and corticosteroids.
• Early superficial subcuticular abscess:
  • Elevation of the eponychial fold by sliding the flat edge of a no. 11 blade (18G needle or small clamps may be used) gently between the proximal nail fold and the nail plate near the point of maximal tenderness
  • A digital nerve block or local anesthesia may be necessary.
• Partial nail involvement:
  • If the lesion extends beneath the nail, remove a longitudinal section of the nail.
  • Petroleum jelly or iodoform gauze packing for 24 hr
• Runaround abscess:
  • If the lesion extends beneath the base of the nail to the other side, remove 1/4–1/3 of the proximal nail with 2 small incisions at the dorsolateral edges of the nail fold and pack eponychial fold with petroleum jelly or iodoform gauze to prevent adherence.
• Extensive subungual abscess:
  • Remove entire nail.
• Early paronychia without purulence present may be managed with warm soaks alone; beyond that, antibiotics are recommended if there is any apparent cellulitis, abscess, or systemic sign of infection.
• Trimethoprim–sulfamethoxazole, dicloxacillin, and amoxicillin–clavulanate are appropriate first-line agents, with treatment regimens ranging from 5–10 days, depending on severity.
• Clindamycin or amoxicillin–clavulanate if associated with nail biting or oral contact

Chronic Paronychia

• Avoidance of predisposing exposures and irritants/chemicals
• Topical steroids should be considered first-line therapy, with or without broad-spectrum topical antifungal agent
• Consideration for antistaphylococcal regimen
• For recalcitrant cases:
  • Eponychial marsupialization involving removal of a crescentic piece of skin just proximal to the nail fold, including all thickened tissue down to but not including germinal matrix
  • Oral antifungal therapy

MEDICATION

First Line

• Amoxicillin–clavulanate: 875 mg PO BID for 7 days (peds: 25 mg/kg/d PO q12h)
• Trimethoprim–sulfamethoxazole (Bactrim DS) BID for 7 days
• Dicloxacillin: 500 mg PO QID for 7 days (peds: 12.5–50 mg/kg/d PO q6h)

Second Line

• Clindamycin: 300 mg PO QID for 7 days (peds: 20–40 mg/kg/d div. q6h PO, IV, IM)
• Topical antibiotics: Polymyxin B/Bacitracin, there is a high incidence of hypersensitivity to neomycin, mucipurin topical (Bactroban), or gentamicin TID for 5–10 days (0.1% ointment)
• Topical antifungal/steroid combination: nystatin–triamcinolone BID–TID until resolution, no longer than 1 mo
• For all topical antibiotics apply a small amount to affected areas TID–QID

[Outline]

• ED TREATMENT/PROCEDURES
• MEDICATION

DISPOSITION

Admission Criteria

Admission is not needed for paronychia alone.

Discharge Criteria

• Patients with uncomplicated paronychias may be discharged with appropriate follow-up instructions.
• Patients with packings should be re-evaluated in 24 hr.

Issues for Referral

Chronic paronychias refractory to treatment

• Acute paronychias respond well to decompression with or without antibiotics.
• Chronic paronychias are largely a result of chronic exposure to allergens/irritants.
• Reiter syndrome and psoriasis can mimic paronychia.
• Recurrent paronychia should raise suspicion for herpetic whitlow.
• Assess for felons.

ICD9

• 112.3 Candidiasis of skin and nails
• 681.02 Onychia and paronychia of finger
• 681.9 Cellulitis and abscess of unspecified digit

ICD10

• B37.2 Candidiasis of skin and nail
• L03.019 Cellulitis of unspecified finger
• L03.039 Cellulitis of unspecified toe

[Outline]

• ICD9
• ICD10

• Dahdah MJ, Scher RK. Nail diseases related to nail cosmetics. Dermatol Clin. 2006;24(2):233–239,vii.
• Jebson PJ. Infections of the fingertip. Paronychias and felons. Hand Clin. 1998;14:547–555, viii.
• Moran GJ, Talan DA. Hand infections. Emerg Med Clin North Am. 1993;11(3):601–619.
• Rigopoulos D, Larios G, Gregoriou S, et al. Acute and chronic paronychia. Am Fam Physician. 2008;77(3):339–346.
• Rockwell PG. Acute and chronic paronychia. Am Fam Physician. 2001;63(6):1113–1116.

Gene Ma