• Acute paronychia(<6 wk): Nail biting, finger sucking, aggressive manicuring or manipulation, ingrown nail, and trauma predispose to development
• Chronic paronychia(>6 wk): Occupations with persistent moist hand s; dish washers, bartenders; also increased in patients with peripheral vascular disease or diabetes

• 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

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

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

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

Acute Paronychia

• Early paronychia without purulence may be managed with warm-water soaks 4 times a day, 15 min per session, without oral antibiotics; may also consider topical antibiotics
• 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
• Simple, uncomplicated paronychia with abscess in patients without immunocompromise can be managed with I&D, warm soaks, and topical antibiotics. However, more extensive abscesses, subungual collections, associated cellulitis, or patients with diabetes/immunocompromised should be treated with oral antibiotics
• Trimethoprim-sulfamethoxazole, dicloxacillin, and amoxicillin-clavulanate are appropriate first-line agents, with treatment regimens ranging from 5-10 d, 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

• Amoxicillin-clavulanate: 875 mg PO b.i.d for 7 d (peds: 25 mg/kg/d PO q12h)
• Trimethoprim-sulfamethoxazole (Bactrim DS) b.i.d for 7 d
• Dicloxacillin: 500 mg PO q.i.d for 7 d (peds: 12.5-50 mg/kg/d PO q6h)
• Topical antibiotics: Polymyxin B/bacitracin, neomycin, mupirocin topical (Bactroban), or gentamicin t.i.d for 5-10 d (0.1% ointment)
• Chronic paronychia: High-potency topical steroid: Applied b.i.d for 2-4 wk

• Clindamycin: 300 mg PO q.i.d for 7 d (peds: 20-40 mg/kg/d div q6h PO, IV, IM)
• Chronic paronychia: Oral itraconazole or terbinafine, or surgical referral for refractory cases

Admission is not needed for paronychia alone

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

Chronic paronychias refractory to treatment for surgical management