What is the treatment for an infected nail and cuticle?

Treatment of Infected Nail and Cuticle

For acute bacterial paronychia (infected cuticle), start with warm compresses and topical antiseptics; if there is purulent drainage or abscess formation, incision and drainage is required along with oral antibiotics covering Staphylococcus aureus. 1

Initial Assessment and Diagnosis

Before initiating treatment, determine whether the infection is:

• Acute bacterial paronychia: Painful, erythematous swelling of the nail fold with rapid onset (hours to days), often with purulent drainage 1
• Chronic paronychia: Gradual onset over weeks to months with nail fold inflammation, often multifactorial (irritants, allergens, and secondary Candida infection) 1
• Fungal infection (onychomycosis): Nail plate involvement with discoloration, thickening, or separation; requires mycological confirmation before systemic treatment 2

Critical pitfall: Do not confuse herpetic whitlow (viral) with bacterial abscess—herpetic whitlow requires non-operative management, while bacterial abscess requires drainage 3

Treatment Algorithm for Acute Bacterial Paronychia

Grade 1 (Mild): Nail fold edema or erythema without purulent drainage

• Warm compresses applied several times daily 1
• Topical antiseptics: Povidone-iodine 2% or octenidine 2, 4
• Topical antibiotics with corticosteroids (e.g., bacitracin applied 1-3 times daily) 2, 5
• Reassess after 2 weeks; if worsening, proceed to next step 2

Grade 2 (Moderate): Pain with discharge or nail plate separation

• Continue topical antiseptics (povidone-iodine 2%) 2
• Obtain bacterial/fungal cultures if infection suspected 2
• Oral antibiotics with anti-Staphylococcus aureus coverage (most common pathogen) 1, 3
• Consider Pseudomonas coverage if green/black nail discoloration present (treat with ciprofloxacin) 4
• Reassess after 2 weeks 2

Grade 3 (Severe): Abscess formation or limiting self-care activities

• Surgical incision and drainage is mandatory for abscess 1, 3
• Obtain bacterial cultures 2
• Oral antibiotics with anti-Staphylococcus aureus and gram-positive coverage 2
• Consider partial nail avulsion if nail plate involvement 2

Treatment for Chronic Paronychia

Topical corticosteroids are more effective than systemic antifungals for chronic paronychia. 1

• Avoid contact irritants (water, chemicals, nail manipulation) 1
• Combination therapy: Broad-spectrum topical antifungal (imidazole lotion) alternating with antibacterial lotion, applied until cuticle integrity restored (may take several months) 2
• Topical corticosteroids to reduce inflammation 1
• Emollient lotions applied regularly 1
• For recalcitrant cases: Consider en bloc excision of proximal nail fold or eponychial marsupialization 1

Treatment for Fungal Nail Infections (If Confirmed)

Do not commence treatment before mycological confirmation (microscopy and culture). 2

Yeast infections (Candida) with paronychia:

• Topical treatment is preferred: Antiseptics applied to proximal nail and beneath cuticle until cuticle integrity restored (several months) 2
• Imidazole lotion alternating with antibacterial lotion is usually effective 2
• If nail plate invaded: Itraconazole 400 mg daily for 1 week per month for 2 months (fingernails) or 3-4 pulses (toenails) 2

Dermatophyte onychomycosis (if nail plate involved):

• Terbinafine is superior to itraconazole and should be first-line: 250 mg daily for 6 weeks (fingernails) or 12 weeks (toenails) 2
• Itraconazole as second-line: 200 mg daily for 12 weeks continuously, or 400 mg daily for 1 week per month (2 pulses for fingernails, 3 for toenails) 2
• Expected cure rates: 80-90% for fingernails, 70-80% for toenails 2

Key Clinical Pearls

• Secondary bacterial or fungal superinfection occurs in up to 25% of paronychia cases—always obtain cultures in Grade 2 or higher 2
• Pseudomonas aeruginosa causes green or black nail discoloration and requires ciprofloxacin 4
• Artificial nails and nail polish harbor microorganisms and should be avoided during treatment 3
• For chronic paronychia, topical steroids are more effective than systemic antifungals 1
• Trauma (mechanical or chemical) is the usual trigger enabling pathogen infiltration 3